UNITED STATES 
SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549


FORM 10-Q

|  |                                                                                           
|- | ------------------------------------------------------------------------------------------
|x | QUARTERLY
  REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 
|  | For the quarterly period
  ended June 30, 2008                                            
|  |                                                                                           
|  | or                                                                                        
|  |                                                                                           
|o | TRANSITION
  REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
|  | For the transition period
  from _______________________to____________________________    

Commission File No. 000-51924

RIDGEWOOD ENERGY O FUND, LLC(Exact name of registrant as specified in its charter)

|                                                                   |                                         
|------------------------------------------------------------------ | ----------------------------------------
|Delaware                                                           | 76-0774429                              
|(State
  or other jurisdiction of
  incorporation or organization) | (I.R.S.
  Employer
  Identification No.)

1314 King Street, Wilmington, Delaware 19801(Address of principal
executive offices) (Zip code)

(302) 888-7444
(Registrants telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act: None 
Securities registered pursuant to Section 12(g) of the Act:

Shares of LLC Membership Interest

Indicate by check mark
whether the registrant (1) has filed all reports required to be filed by
Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding
12 months (or for such shorter period that the registrant was required to file
such reports) and (2) has been subject to such filing requirements for the past
90 days.     Yes x  No o

Indicate by check mark
whether the registrant is a large accelerated filer, an accelerated filer, a
non-accelerated filer, or a smaller reporting company. See definitions of
large accelerated filer, accelerated filer, and smaller reporting company
in Rule 12b-2 of the Exchange Act. (Check one):

|                                                |   |                           |  
|----------------------------------------------- | - | ------------------------- | -
|Large accelerated filer                         | o | Accelerated filer         | o
|Non-accelerated filer                           | o | Smaller reporting company | x
|(Do not check if a smaller
  reporting company) |   |                           |  

Indicate by check mark
whether the registrant is a shell company (as defined in Rule 12b-2 of the
Act). Yes o  No x

There is no market for the
shares. As of August 1, 2008 there are 870.6486 shares outstanding.

---



Table of Contents

|                               |                                                                                                          |  |     
|------------------------------ | -------------------------------------------------------------------------------------------------------- |  | ----
|                               |                                                                                                          |  | Page
|PART I - FINANCIAL INFORMATION |                                                                                                          | 
|Item 1.                        | Financial
  Statements:                                                                                  |  |     
|                               | Unaudited Condensed Balance Sheets
as of June 30,
  2008 and December 31, 2007                           |  | 2   
|                               | Unaudited Condensed Statements of
Operations for the
  three and six months ended June 30, 2008 and 2007 |  | 3   
|                               | Unaudited Condensed Statements of
Cash Flows for the
  six months ended June 30, 2008 and 2007           |  | 4   
|                               | Notes to
  Unaudited Condensed Financial Statements                                                      |  | 5   
|Item 2.                        | Managements
  Discussion and Analysis of Financial Condition and Results of Operations                  |  | 11  
|Item 3.                        | Quantitative
  and Qualitative Disclosures about Market Risk                                             |  | 16  
|Item 4.                        | Controls
  and Procedures                                                                                |  | 16  
|                               |                                                                                                          |  |     
|PART II - OTHER INFORMATION    |                                                                                                          | 
|                               |                                                                                                          |  |     
|Item 1.                        | Legal
  Proceedings                                                                                      |  | 17  
|Item 1A.                       | Risk
  Factors                                                                                           |  | 17  
|Item 2.                        | Unregistered
  Sales of Equity Securities and Use of Proceeds                                            |  | 17  
|Item 3.                        | Defaults
  Upon Senior Securities                                                                        |  | 17  
|Item 4.                        | Submissions
  of Matters to a Vote of Security Holders                                                   |  | 17  
|Item 5.                        | Other
  Information                                                                                      |  | 17  
|Item 6.                        | Exhibits                                                                                                 |  | 17  
|                               |                                                                                                          |  |     
|                               | SIGNATURES                                                                                               |  | 18  

1

---



PART I - FINANCIAL INFORMATION ITEM 1. FINANCIAL STATEMENTS

RIDGEWOOD ENERGY O FUND, LLC UNAUDITED CONDENSED BALANCE SHEETS
(in thousands, except share data)

|                                                                               |  |               |         |                   |   |         |  
|------------------------------------------------------------------------------ |  | ------------- | ------- | ----------------- | - | ------- | -
|                                                                               |  | June 30, 2008 |         | December 31, 2007 |  
|                                                                               |  |               |         |                   |  
|ASSETS                                                                         |  |               |         |                   |   |         |  
|Current assets:                                                                |  |               |         |                   |   |         |  
|Cash and cash equivalents                                                      |  | $             | 17,459  |                   | $ | 14,546  |  
|Short-term investments in marketable securities                                |  |               | 28,087  |                   |   | 40,602  |  
|Production receivable                                                          |  |               | 1,654   |                   |   | 598     |  
|Other current assets                                                           |  |               | 1,496   |                   |   | 372     |  
|                                                                               |  |               |         |                   |   |         |  
|Total current assets                                                           |  |               | 48,696  |                   |   | 56,118  |  
|Salvage fund                                                                   |  |               | 1,126   |                   |   | 1,110   |  
|Oil and gas properties:                                                        |  |               |         |                   |   |         |  
|Advances to operators for working interests and
expenditures                   |  |               | 1,675   |                   |   | 1,866   |  
|Unproved properties                                                            |  |               | 4,951   |                   |   | 5,961   |  
|Proved properties                                                              |  |               | 9,849   |                   |   | 5,603   |  
|Less: accumulated depletion and amortization                                   |  |               | (2,870  | )                 |   | (701    | )
|                                                                               |  |               |         |                   |   |         |  
|Total oil and gas properties                                                   |  |               | 13,605  |                   |   | 12,729  |  
|                                                                               |  |               |         |                   |   |         |  
|                                                                               |  |               |         |                   |   |         |  
|Total assets                                                                   |  | $             | 63,427  |                   | $ | 69,957  |  
|                                                                               |  |               |         |                   |   |         |  
|                                                                               |  |               |         |                   |   |         |  
|LIABILITIES
  AND MEMBERS CAPITAL                                             |  |               |         |                   |   |         |  
|Current liabilities:                                                           |  |               |         |                   |   |         |  
|Due to operators                                                               |  | $             | 5,747   |                   | $ | 2,070   |  
|Accrued expenses payable                                                       |  |               | 133     |                   |   | 126     |  
|Due to affiliates (Note 6)                                                     |  |               |        |                   |   | 652     |  
|                                                                               |  |               |         |                   |   |         |  
|Total current liabilities                                                      |  |               | 5,880   |                   |   | 2,848   |  
|                                                                               |  |               |         |                   |   |         |  
|Asset retirement obligations                                                   |  |               | 201     |                   |   | 39      |  
|                                                                               |  |               |         |                   |   |         |  
|Total liabilities                                                              |  |               | 6,081   |                   |   | 2,887   |  
|                                                                               |  |               |         |                   |   |         |  
|Commitments and contingencies (Note 8)                                         |  |               |         |                   |   |         |  
|Members capital:                                                              |  |               |         |                   |   |         |  
|Manager:                                                                       |  |               |         |                   |   |         |  
|Distributions                                                                  |  |               | (471    | )                 |   | (73     | )
|Accumulated deficit                                                            |  |               | (837    | )                 |   | (1,447  | )
|                                                                               |  |               |         |                   |   |         |  
|Managers total                                                                |  |               | (1,308  | )                 |   | (1,520  | )
|                                                                               |  |               |         |                   |   |         |  
|Shareholders:                                                                  |  |               |         |                   |   |         |  
|Capital contributions (935 shares authorized; 870.6486 issued and
outstanding) |  |               | 128,990 |                   |   | 128,990 |  
|Syndication costs                                                              |  |               | (14,742 | )                 |   | (14,742 | )
|Distributions                                                                  |  |               | (2,672  | )                 |   | (414    | )
|Accumulated deficit                                                            |  |               | (52,922 | )                 |   | (45,244 | )
|                                                                               |  |               |         |                   |   |         |  
|Shareholders total                                                            |  |               | 58,654  |                   |   | 68,590  |  
|                                                                               |  |               |         |                   |   |         |  
|                                                                               |  |               |         |                   |   |         |  
|Total members capital                                                         |  |               | 57,346  |                   |   | 67,070  |  
|                                                                               |  |               |         |                   |   |         |  
|                                                                               |  |               |         |                   |   |         |  
|Total liabilities and members capital                                         |  | $             | 63,427  |                   | $ | 69,957  |  
|                                                                               |  |               |         |                   |   |         |  

The accompanying notes are an integral part of these unaudited
condensed financial statements.

2

---



RIDGEWOOD ENERGY O FUND, LLCUNAUDITED CONDENSED STATEMENTS OF OPERATIONS
(in thousands, except share data)

|                                      |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|------------------------------------- |  | --------------------------- | ------ | ------------------------- | - | ------ | - | ---- | ------ | - | - | ------ | -
|                                      |  | Three months ended June 30, |        | Six months ended June 30, |  
|                                      |  | 2008                        |        | 2007                      |   | 2008   |   | 2007 |       
|                                      |  |                             |        |                           |   |        |   |      |       
|Revenue                               |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Oil and gas revenue                   |  | $                           | 4,046  |                           | $ |       |   | $    | 6,461  |   | $ |       |  
|                                      |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Expenses                              |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Depletion and amortization            |  |                             | 1,349  |                           |   |       |   |      | 2,169  |   |   |       |  
|Dry-hole costs                        |  |                             | 9,857  |                           |   | 5      |   |      | 10,281 |   |   | 1,855  |  
|Management fees to affiliate (Note 6) |  |                             | 549    |                           |   | 587    |   |      | 1,101  |   |   | 1,174  |  
|Casualty loss                         |  |                             |       |                           |   | 3,468  |   |      |       |   |   | 3,468  |  
|Operating expenses                    |  |                             | 105    |                           |   | 39     |   |      | 137    |   |   | 40     |  
|General and administrative expenses   |  |                             | 258    |                           |   | 138    |   |      | 457    |   |   | 234    |  
|                                      |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Total expenses                        |  |                             | 12,118 |                           |   | 4,237  |   |      | 14,145 |   |   | 6,771  |  
|                                      |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Loss from operations                  |  |                             | (8,072 | )                         |   | (4,237 | ) |      | (7,684 | ) |   | (6,771 | )
|                                      |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Other
  income                        |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Interest income                       |  |                             | 180    |                           |   | 658    |   |      | 616    |   |   | 1,372  |  
|                                      |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Net loss                              |  | $                           | (7,892 | )                         | $ | (3,579 | ) | $    | (7,068 | ) | $ | (5,399 | )
|                                      |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|                                      |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Manager Interest                      |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Net income (loss)                     |  | $                           | 370    |                           | $ | (134   | ) | $    | 610    |   | $ | (244   | )
|                                      |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Shareholder Interest                  |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Net loss                              |  | $                           | (8,262 | )                         | $ | (3,445 | ) | $    | (7,678 | ) | $ | (5,155 | )
|Net loss per share                    |  | $                           | (9,489 | )                         | $ | (3,956 | ) | $    | (8,819 | ) | $ | (5,921 | )

The accompanying notes are an integral part of these unaudited condensed
financial statements.

3

---



RIDGEWOOD ENERGY O FUND, LLCUNAUDITED CONDENSED STATEMENTS OF CASH FLOWS
(in thousands)

|                                                                                                  |  |                           |         |      |   |         |  
|------------------------------------------------------------------------------------------------- |  | ------------------------- | ------- | ---- | - | ------- | -
|                                                                                                  |  | Six months ended June 30, |        
|                                                                                                  |  | 2008                      |         | 2007 |  
|                                                                                                  |  |                           |         |      |  
|Cash flows from operating activities                                                              |  |                           |         |      |   |         |  
|Net loss                                                                                          |  | $                         | (7,068  | )    | $ | (5,399  | )
|Adjustments to reconcile net loss to net cash provided by (used in)
  operating activities        |  |                           |         |      |   |         |  
|Depletion and amortization                                                                        |  |                           | 2,169   |      |   |        |  
|Dry-hole costs                                                                                    |  |                           | 10,281  |      |   | 1,855   |  
|Casualty loss                                                                                     |  |                           |        |      |   | 3,468   |  
|Accretion expense                                                                                 |  |                           | 3       |      |   | 1       |  
|Interest earned on marketable securities                                                          |  |                           | (374    | )    |   | (967    | )
|Changes in assets and liabilities:                                                                |  |                           |         |      |   |         |  
|Increase in production receivable                                                                 |  |                           | (1,056  | )    |   |        |  
|(Increase) decrease in other current assets                                                       |  |                           | (809    | )    |   | 34      |  
|Increase in accrued expenses payable                                                              |  |                           | 1       |      |   | 14      |  
|Decrease in due to affiliates                                                                     |  |                           | (652    | )    |   |        |  
|                                                                                                  |  |                           |         |      |   |         |  
|Net cash provided by (used in) operating activities                                               |  |                           | 2,495   |      |   | (994    | )
|                                                                                                  |  |                           |         |      |   |         |  
|                                                                                                  |  |                           |         |      |   |         |  
|Cash flows from investing activities                                                              |  |                           |         |      |   |         |  
|Payments to operators for working interests and
expenditures                                      |  |                           | (1,675  | )    |   |        |  
|Capital expenditures for oil and gas properties                                                   |  |                           | (8,124  | )    |   | (8,708  | )
|Interest reinvested in salvage fund                                                               |  |                           | (16     | )    |   | (17     | )
|Proceeds from the sale of marketable securities                                                   |  |                           | 40,889  |      |   | 25,644  |  
|Investment in marketable securities                                                               |  |                           | (28,000 | )    |   | (25,318 | )
|                                                                                                  |  |                           |         |      |   |         |  
|Net cash provided by (used in) investing activities                                               |  |                           | 3,074   |      |   | (8,399  | )
|                                                                                                  |  |                           |         |      |   |         |  
|                                                                                                  |  |                           |         |      |   |         |  
|Cash flows from financing activities                                                              |  |                           |         |      |   |         |  
|Distributions                                                                                     |  |                           | (2,656  | )    |   |        |  
|                                                                                                  |  |                           |         |      |   |         |  
|Net cash used in financing activities                                                             |  |                           | (2,656  | )    |   |        |  
|                                                                                                  |  |                           |         |      |   |         |  
|Net increase (decrease) in cash and cash equivalents                                              |  |                           | 2,913   |      |   | (9,393  | )
|                                                                                                  |  |                           |         |      |   |         |  
|Cash and cash equivalents, beginning of period                                                    |  |                           | 14,546  |      |   | 33,188  |  
|                                                                                                  |  |                           |         |      |   |         |  
|Cash and cash equivalents, end of period                                                          |  | $                         | 17,459  |      | $ | 23,795  |  
|                                                                                                  |  |                           |         |      |   |         |  
|                                                                                                  |  |                           |         |      |   |         |  
|Supplemental schedule of non-cash investing
  activities                                          |  |                           |         |      |   |         |  
|                                                                                                  |  |                           |         |      |   |         |  
|Advances used for capital expenditures in oil and gas properties
  reclassified to dry-hole costs |  | $                         | 1,866   |      | $ |        |  
|                                                                                                  |  |                           |         |      |   |         |  

The accompanying notes are an integral part of these unaudited condensed
financial statements.

4

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RIDGEWOOD ENERGY O FUND, LLC NOTES TO UNAUDITED CONDENSED FINANCIAL STATEMENTS

1.Organization and Purpose

The Ridgewood Energy O Fund,
LLC (the Fund), a Delaware limited liability company, was formed on December
21, 2004 and operates pursuant to a limited liability company agreement (the
LLC Agreement) dated as of February 16, 2005 by and among Ridgewood Energy
Corporation (the Manager) and the shareholders of the Fund.

The Fund was organized to
acquire interests in oil and natural gas properties located in the United
States offshore waters of Texas, Louisiana and Alabama in the Gulf of Mexico.
During 2007, the Fund began
earning revenue and was determined to no longer be an exploratory stage
enterprise.

The Manager performs, or
arranges for the performance of, the management and administrative services
required for Fund operations. Such services include, without limitation, the
administration of shareholder accounts, shareholder relations and the
preparation, review and dissemination of tax and other financial information.
In addition, the Manager provides office space, equipment and facilities and
other services necessary for Fund operations. The Manager also engages and
manages the contractual relations with unaffiliated custodians, depositories,
accountants, attorneys, broker-dealers, corporate fiduciaries, insurers, banks
and others as required. See Notes 2, 6 and 8.

2.Summary of Significant Accounting Policies

Basis of Presentation

These unaudited interim
condensed financial statements have been prepared by the Funds management in
accordance with accounting principles generally accepted in the United States
of America (GAAP) and in the opinion of management, contain all adjustments
(consisting of only normal recurring adjustments) necessary to present fairly
the Funds financial position, results of operations and cash flows for the
periods presented. Certain information and note disclosures normally included
in annual financial statements prepared in accordance with GAAP have been
omitted in these unaudited interim condensed financial statements. The results
of operations, financial position, and cash flows for the periods presented
herein are not necessarily indicative of future financial results. These unaudited
interim condensed financial statements should be read in conjunction with the
annual financial statements and the notes thereto for the year ended December
31, 2007 included in the Funds Annual Report on Form 10-K (Form 10-K) filed
with the Securities and Exchange Commission (the SEC).

Use of Estimates

The preparation of financial
statements in conformity with GAAP requires management to make estimates and
assumptions that affect the reported amounts of assets and liabilities and
disclosure of contingent assets and liabilities as of the date of the financial
statements and the reported amounts of revenues and expenses during the
reporting period. On an ongoing basis, the Manager reviews its estimates,
including those related to amounts advanced to and billed by operators,
determination of proved reserves, impairments and asset retirement obligations.
Actual results may differ from those estimates.

Cash and Cash Equivalents

All highly liquid
investments with maturities, when purchased, of three months or less are
considered cash and cash equivalents. At times, bank deposits may be in excess
of federally insured limits. At June 30, 2008 and December 31, 2007, bank
balances, inclusive of salvage fund, exceeded federally insured limits by $7.3
million and $14.4 million, respectively. The Fund maintains bank deposits with
accredited financial institutions.

Investments in Marketable Securities

At times the Fund may
purchase investments comprised of U.S. Treasury Bills and Notes. These
investments are considered short-term when their maturities, when purchased, are greater than
three months and one year or less, and long-term when their maturities are in
excess of twelve months. The Fund currently has short-term investments that are
classified as held-to-maturity. Held-to-maturity securities are those
investments that the Fund has the ability and intent to hold until maturity,
and are recorded at cost plus accrued income, adjusted for the amortization of
premiums and discounts, which approximate fair value. At June 30, 2008, the
Fund had short-term held-to-maturity investments totaling $28.1 million, which
mature in October 2008 and November 2008. At December 31, 2007 the Fund had
short-term held-to-maturity investments totaling $40.6 million.

5

---



For all investments,
interest income is accrued as earned and amortization of premium or discount,
if any, is included in interest income.

Salvage Fund

Pursuant to the Funds LLC
Agreement, the Fund deposits in a separate interest-bearing account, or a
salvage fund, money to provide for dismantling production platforms and
facilities, plugging and abandoning the wells and removing the platforms,
facilities and wells after their useful lives, in accordance with applicable
federal and state laws and regulations. At June 30, 2008 and December 31, 2007,
the Fund had held-to-maturity investments within its salvage fund totaling $1.1
million. The held-to-maturity investment held within the salvage fund at June
30, 2008 matures in February 2012.

Interest earned on the
account will become part of the salvage fund. There are no restrictions on
withdrawals from the salvage fund.

Oil and Gas
Properties

Investments in oil and gas
properties are operated by unaffiliated entities (Operators) who are
responsible for drilling, administering and producing activities pursuant to
the terms of the applicable operating agreements with working interest owners.
The Funds portion of exploration, drilling, operating and capital equipment
expenditures relating to the wells are advanced and billed by the Operators
through authorization for expenditures.

The successful efforts
method of accounting for oil and gas producing activities is followed.
Acquisition costs are capitalized when incurred. Other oil and gas exploration
costs, excluding the costs of drilling exploratory wells, are charged to
expense as incurred. The costs of drilling exploratory wells are capitalized
pending the determination of whether the wells have discovered proved
commercial reserves. If proved commercial reserves have not been found,
exploratory drilling costs are expensed to dry-hole expense. Costs to develop
proved reserves, including the costs of all development wells and related
facilities and equipment used in the production of crude oil and gas, are
capitalized. Expenditures for ongoing repairs and maintenance of producing
properties are expensed as incurred.

Upon the sale or retirement
of a proved property, the cost and related accumulated depletion and
amortization will be eliminated from the property accounts, and the resultant
gain or loss is recognized. On the sale or retirement of an unproved property,
gain or loss on the sale is recognized. The Manager does not currently intend
to sell any of the Funds property interests.

Capitalized acquisition
costs of producing oil and gas properties are depleted by the
unit-of-production method.

As of June 30, 2008, amounts
recorded in due to operators totaling $5.7 million related to capital
expenditures for oil and gas property. These amounts were paid during the third
quarter of 2008.

Advances to
Operators for Working Interests and Expenditures

The Funds acquisition of a
working interest in a well or a project requires it to make a payment to the
seller for the Funds rights, title and interest. The Fund is required to
advance its share of estimated cash expenditures for the succeeding months
operation. The Fund accounts for such payments as advances to operators for
working interests and expenditures. As drilling costs are incurred, the
advances are transferred to unproved properties.

6

---



Asset Retirement
Obligations

For oil and gas properties,
there are obligations to perform removal and remediation activities when the
properties are retired. When a project reaches drilling depth and is determined
to be either proved or dry, an asset retirement obligation is incurred. Plug
and abandonment costs associated with unsuccessful projects are expensed as
dry-hole costs. The table below presents changes in asset retirement
obligations for the six months ended June 30, 2008 and the year ended December
31, 2007.

|                                |  |                |        |                   |   |      |  
|------------------------------- |  | -------------- | ------ | ----------------- | - | ---- | -
|                                |  | June 30, 2008  |        | December 31, 2007 |  
|                                |  |                |        |                   |  
|                                |  | (in thousands) |       
|Balance -
  Beginning of period |  | $              | 39     |                   | $ | 37   |  
|Liabilities
  incurred          |  |                | 6,608  |                   |   | 904  |  
|Liabilities
  settled           |  |                | (6,449 | )                 |   | (904 | )
|Accretion
  expense             |  |                | 3      |                   |   | 2    |  
|                                |  |                |        |                   |   |      |  
|Balance - End
  of period       |  | $              | 201    |                   | $ | 39   |  
|                                |  |                |        |                   |   |      |  

As indicated above, the Fund
maintains a salvage fund to provide for the funding of future asset retirement
obligations.

Syndication Costs

Direct costs associated with
offering the Funds shares including professional fees, selling expenses and
administrative costs payable to the Manager, an affiliate of the Manager and
unaffiliated broker-dealers are reflected as a reduction of shareholders
capital.

Revenue
Recognition and Imbalances

Oil and natural gas revenues
are recognized when production is sold to a purchaser at a fixed or
determinable price, when delivery has occurred and title has transferred, and
if collectibility of the revenue is probable.

The Fund uses the sales
method of accounting for gas production imbalances. The volumes of gas sold may
differ from the volumes to which the Fund is entitled based on its interests in
the properties. These differences create imbalances that are recognized as a
liability only when the properties estimated remaining reserves net to the
Fund will not be sufficient to enable the underproduced owner to recoup its
entitled share through production. The Funds recorded liability, if any, would
be reflected in other non-current liabilities. No receivables are recorded for
those wells where the Fund has taken less than its share of production.
Gas imbalances are reflected as adjustments to estimates of proved gas reserves
and future cash flows. At June 30, 2008 and December 31, 2007, there were no
oil or natural gas balancing arrangements between the Fund and other working
interest owners.

Impairment of
Long-Lived Assets

In accordance with the
provisions of Statement of Financial Accounting Standards (SFAS) No. 144,
Accounting for the Impairment of Long-Lived Assets, long-lived assets,
such as oil and natural gas properties, are evaluated when events or changes in
circumstances indicate the carrying value of such assets may not be
recoverable. The determination of whether impairment has occurred is made by
comparing the carrying values of long-lived assets to the estimated future
undiscounted cash flows attributable to the asset. The impairment loss
recognized is the excess of the carrying value over the future discounted cash
flows attributable to the asset or the estimated fair value of the
asset. During the three and six months ended June 30, 2008 and 2007, no
impairments were recorded.

Depletion and
Amortization

Depletion and amortization
of the cost of proved oil and natural gas properties are calculated using the
units-of-production method. Proved developed reserves are used as the base for
depleting the cost of successful exploratory drilling and development costs.
The sum of proved developed and proved undeveloped reserves is used as the base
for depleting, or amortizing, leasehold acquisition costs, the costs to acquire
proved properties and platform and pipeline costs. The Fund began production
during the third quarter 2007.

Income Taxes

No provision is made for
income taxes in the financial statements. The Fund is a limited liability
company, and as such, the Funds income or loss is passed through and included
in the tax returns of the Funds shareholders.

Income and
Expense Allocation

Profits and losses are
allocated 85% to shareholders in proportion to their relative capital
contributions and 15% to the Manager, except for interest income and certain
expenses such as dry-hole costs, fiduciary fees, depletion and amortization,
which are allocated 99% to shareholders and 1% to the Manager.

7

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3.
Recent Accounting Standards

In May 2008, the Financial
Accounting Standards Board (FASB) issued SFAS No. 162, The Hierarchy of
Generally Accepted Accounting Principles, (SFAS No.162), which identifies
the sources of accounting principles and the framework for selecting the principles
used in the preparation of financial statements that are presented in
conformity with U.S. generally accepted accounting principles (GAAP). SFAS
No. 162 will be effective sixty days following the Securities and Exchange
Commissions approval of the Public Company Accounting Oversight Board
amendments to AU Section 411. The Fund does not expect the adoption of SFAS No.
162 will have a material impact on its financial condition or results of
operation.

In September 2006, the FASB
issued SFAS No. 157, Fair Value Measurements, (SFAS No.157), which applies
under most other accounting pronouncements that require or permit fair value
measurements. SFAS No. 157 provides a common definition of fair value as the
price that would be received to sell an asset or paid to transfer a liability
in a transaction between market participants. The new standard also provides
guidance on the methods used to measure fair value and requires expanded
disclosures related to fair value measurements. SFAS No. 157 had originally
been effective for financial statements issued for fiscal years beginning after
November 15, 2007, however the FASB has agreed on a one year deferral for all
non-financial assets and liabilities. On January 1, 2008, the Fund adopted SFAS
No. 157 for financial assets and liabilities.

4. Unproved Properties -
Capitalized Exploratory Well Costs

Leasehold acquisition and
exploratory drilling costs are capitalized pending determination of whether the
well has found proved reserves. Unproved properties are assessed on a quarterly
basis by evaluating and monitoring if sufficient progress is made on assessing
the reserves.

The following table reflects
the net changes in unproved properties for the six months ended June 30, 2008
and the year ended December 31, 2007. As of June 30, 2008, the Fund had no
capitalized exploratory well costs greater than one year.

|                                                                                                 |  |                |        |                   |   |        |  
|------------------------------------------------------------------------------------------------ |  | -------------- | ------ | ----------------- | - | ------ | -
|                                                                                                 |  | June 30, 2008  |        | December 31, 2007 |  
|                                                                                                 |  |                |        |                   |  
|                                                                                                 |  | (in thousands) |       
|Balance
  - Beginning of the period                                                              |  | $              | 5,961  |                   | $ |       |  
|Additions
  to capitalized exploratory well costs pending the determination of proved
  reserves |  |                | 6,608  |                   |   | 7,647  |  
|Reclassifications
  to proved properties based on the determination of proved reserves           |  |                | (2,621 | )                 |   | (1,686 | )
|Capitalized
  exploratory well costs charged to dry-hole costs                                   |  |                | (4,997 | )                 |   |       |  
|                                                                                                 |  |                |        |                   |   |        |  
|                                                                                                
|Balance
  - End of the period                                                                    |  | $              | 4,951  |                   | $ | 5,961  |  
|                                                                                                 |  |                |        |                   |   |        |  

Capitalized costs are
expensed as dry-hole costs in the event that reserves are not found or are not
in sufficient quantities to complete the well and develop the field. During the
three and six months ended June 30, 2008, certain wells received credits from
their respective operators upon review and audit of the wells costs. Dry-hole
costs are detailed in the table below.

|                                |  |                             |       |                           |   |      |   |      |        |   |   |       | 
|------------------------------- |  | --------------------------- | ----- | ------------------------- | - | ---- | - | ---- | ------ | - | - | ----- | 
|                                |  | Three months ended June 30, |       | Six months ended June 30, |  
|Lease Block                     |  | 2008                        |       | 2007                      |   | 2008 |   | 2007 |       
|                                |  |                             |       |                           |   |      |   |      |       
|                                |  | (in thousands)              |      
|High Island 38                  |  | $                           | 6,406 |                           | $ |     |   | $    | 6,406  |   | $ |      | 
|Walker Ridge
  155              |  |                             | 2,246 |                           |   |     |   |      | 2,246  |   |   |      | 
|South Marsh
  Island 213        |  |                             | 1,251 |                           |   |     |   |      | 1,688  |   |   |      | 
|Eugene Island
  346/347 well #3 |  |                             | 275   |                           |   |     |   |      | 275    |   |   |      | 
|West Delta 95                   |  |                             | (320  | )                         |   | 11   |   |      | (334   | ) |   | 1,836 | 
|Other wells                     |  |                             | (1    | )                         |   | (6   | ) |      |       |   |   | 19    | 
|                                |  |                             |       |                           |   |      |   |      |        |   |   |       | 
|                                |  | $                           | 9,857 |                           | $ | 5    |   | $    | 10,281 |   | $ | 1,855 | 
|                                |  |                             |       |                           |   |      |   |      |        |   |   |       | 

5. Distributions

Distributions to
shareholders are allocated in proportion to the number of shares held.

The Manager will determine
whether available cash from operations, as defined in the Funds LLC Agreement,
is to be distributed. Such distributions will be allocated 85% to the
shareholders and 15% to the Manager, as required by the Funds LLC Agreement.

8

---



Available cash from
dispositions, as defined in the Funds LLC Agreement, will be paid 99% to
shareholders and 1% to the Manager until the shareholders have received total
distributions equal to their capital contributions. After shareholders have
received distributions equal to their capital contributions, 85% of available
cash from dispositions will be distributed to shareholders and 15% to the
Manager.

The Fund began making
distributions in December 2007. The shareholders and Manager received
distributions of $2.3 million and $0.4 million for the six months ended June
30, 2008, respectively. There were no distributions paid during the six months
ended June 30, 2007.

6. Related Parties

The Funds LLC Agreement
provides that the Manager render management, administrative and advisory
services. For such services, the Manager receives an annual management fee,
payable monthly, of 2.5% of total capital contributions, net of cumulative
dry-hole and related well costs incurred by the Fund. Management fees for the
three and six months ended June 30, 2008 were $0.5 and $1.1 million,
respectively. For the three and six months ended June 30, 2007 management fees
were $0.6 and $1.2 million, respectively.

From time to time,
short-term payables and receivables, which do not bear interest, arise from
transactions with affiliates in the ordinary course of business. At June 30,
2008 there were no such amounts payable or receivable. At December 31, 2007,
the Fund owed affiliates $0.7 million related to insurance proceeds and revenue
allocations.

None of the compensation
paid to the Manager has been derived as a result of arms length negotiations.

The Fund has working
interest ownership in certain projects to acquire and develop oil and natural
gas projects with other entities that are likewise managed by the Manager.

7. Fair Value of Financial
Instruments

At June 30, 2008 and
December 31, 2007, the carrying value of cash and cash equivalents, short-term
investments in marketable securities, salvage fund, production receivable and
accrued expenses approximated fair value.

8. Commitments and Contingencies

Capital
Commitments

The Fund has entered into
multiple offshore operating agreements for the drilling and development of its
investment properties. The estimated capital expenditures associated with these
agreements vary depending on the stage of development on a property-by-property
basis. As of June 30, 2008, the Fund had committed to spend an additional $3.8
million relating to the properties.

Environmental
Considerations

The exploration for and
development of oil and natural gas involves the extraction, production and
transportation of materials which, under certain conditions, can be hazardous
or cause environmental pollution problems. The Manager and the Operators are
continually taking action they believe appropriate to satisfy applicable
federal, state and local environmental regulations and do not currently
anticipate that compliance with federal, state and local environmental
regulations will have a material adverse effect upon capital expenditures,
results of operations or the competitive position of the Fund in the oil and
natural gas industry. However, due to the significant public and governmental
interest in environmental matters related to those activities, the Manager
cannot predict the effects of possible future legislation, rule changes, or
governmental or private claims. At June 30, 2008 and December 31, 2007, there
were no known environmental contingencies that required the Fund to record a
liability.

Insurance
Coverage

The Fund is
subject to all risks inherent in the exploration for and development of oil and
natural gas. Insurance coverage as is customary for entities engaged in similar
operations is maintained, but losses may occur from uninsurable risks or
amounts in excess of existing insurance coverage. The occurrence of an event
which is not insured or not fully insured could have an adverse impact upon
earnings and financial position. Moreover, insurance is obtained as a package
covering all of the Managers investment programs. Claims made by other such
programs can reduce or eliminate insurance for the Fund.

9

---



Suspension of MMS
Royalty Relief

Under Mineral Management
Services (MMS) rules, the Fund is eligible for annual royalty relief provided
that the average New York Mercantile Exchange (NYMEX) sales price for
shallow water, deep natural gas (Average NYMEX Price) does not exceed price
thresholds established by the MMS, which will be published during the first
quarter of 2009. The Average NYMEX Price during the six months ended June 30,
2008 was $10.10. Based upon current estimations of the 2008 price threshold by
the MMS, in the event the Average NYMEX Price exceeds $10.68 for the second
half of 2008, royalty relief would be suspended and the Fund would be obligated
to pay its previously relieved MMS royalties. In addition, the Funds future
reserve estimates report for natural gas would be reduced by 16.67%. The
reduction in revenues resulting from an obligation to pay these royalties and
subsequent reduction of proved reserves could have a material adverse effect on
the Funds results of operations. If the Average NYMEX Price is below the
threshold established by the MMS, the Fund would not have an obligation to pay
royalties for those properties which qualify for royalty relief and the reserve
balances would not be reduced. With regard to the shallow water, deep natural
gas properties, there was no reduction in reserves for potential future royalties
as of December 31, 2007 as a result of the average 2007 NYMEX price for
gas being below the price threshold.

The Funds natural gas
revenues for the six months ended June 30, 2008 would be reduced by $0.7
million if the 2008 annual Average NYMEX Price ultimately exceeds the price
threshold established by the MMS. At June 30, 2008, the Fund has not recorded a
liability associated with this contingency, based upon the Managers assessment
of its probability; however, the Fund has prepaid the MMS this amount, which is
included in other current assets, to avoid the incurrence of potential interest
charges.

10

---



ITEM 2. MANAGEMENTS DISCUSSION AND ANALYSIS OF FINANCIAL
CONDITION AND RESULTS OF OPERATIONS

Cautionary Statement Regarding
Forward-Looking Statements

Certain statements in this
quarterly report on Form 10-Q (Quarterly Report) and the documents
Ridgewood Energy O Fund, LLC (the Fund) has incorporated by reference into
this Quarterly Report, other than purely historical information, including estimates,
projections, statements relating to the Funds business plans, strategies,
objectives and expected operating results, and the assumptions upon which those
statements are based, are forward-looking statements within the meaning of
the Private Securities Litigation Reform Act of 1995, Section 27A of the
Securities Act of 1933, as amended (the Securities Act) and Section 21E
of the Securities Exchange Act of 1934 (the Exchange Act). These
forward-looking statements generally are identified by the words believe,
project, expect, anticipate, estimate, intend, strategy, plan,
target, pursue, may, will, would, will be, will continue, will
likely result, and similar expressions. Forward-looking statements are based on
current expectations and assumptions that are subject to risks and
uncertainties which may cause actual results to differ materially from the
forward-looking statements. Examples of such events that could cause actual
results to differ materially from historical results or those anticipated
include weather conditions, such as hurricanes, changes in market conditions
affecting the pricing of oil and natural gas, the cost and availability of
equipment, and changes in governmental regulations. The Fund undertakes no
obligation to update or revise publicly any forward-looking statements, whether
as a result of new information, future events or otherwise.

Critical Accounting Policies and
Estimates

The following discussion and
analysis of the Funds financial condition and operating results is based on
its financial statements. The preparation of this Quarterly Report requires the
Fund to make estimates and assumptions that affect the reported amount of
assets and liabilities, disclosure of contingent assets and liabilities at the
date of the Funds financial statements, and the reported amount of revenue and
expenses during the reporting period. Actual results may differ from those
estimates and assumptions. See Notes to Unaudited Condensed Financial
Statements in Part I of this Quarterly Report on Form 10-Q for a presentation
of the Funds significant accounting policies. No changes have been made to the
Funds critical accounting policies and estimates disclosed in its 2007 Annual
Report on Form 10-K.

Overview of the Funds Business

The Fund is a Delaware
limited liability company formed on December 21, 2004 to acquire interests
primarily in oil and natural gas projects located in the U.S. waters of the
Gulf of Mexico. Ridgewood Energy Corporation (Ridgewood Energy or the
Manager) a Delaware corporation, is the Manager. As the Manager, Ridgewood
Energy has direct and exclusive control over the management and control of Fund
operations. The Funds primary investment objective is to generate cash flow
for distribution to the Funds shareholders through participation in oil and
natural gas exploration and development projects in the Gulf of Mexico.

The Manager performs certain
duties on the Funds behalf including the evaluation of potential projects for
investment and ongoing management, administrative and advisory services
associated with these projects. For these services, the Manager receives an
annual management fee equal to 2.5% of capital contributions, net of cumulative
dry-hole and related well costs incurred by the Fund, payable monthly. The Fund
does not currently, nor is there any plan to operate any project in which the
Fund participates. The Manager enters into operating agreements with
third-party operators (Operators) for the management of all exploration,
development and producing operations, as appropriate. The Manager also
participates in distributions.

Business Update

The Fund owns working
interests and has participated in the drilling of fifteen wells, nine of which
have been determined to be dry holes, four that have been determined to be
successful, and two that are currently drilling or scheduled to drill.

Currently Drilling

Ruby Project

In
May 2008, the Fund acquired a 10.0% working interest in the Ruby Project, an
exploratory project operated by PetroQuest Energy, L.L.C. (PetroQuest). The
project is located in the Eugene Island region of the Gulf of Mexico. The well
began drilling in June 2008 and results are expected in August 2008. Through
June 30, 2008, the Fund has spent $2.0 million on this well, for which the
total estimated budget is $3.5 million.

11

---



South Timbalier
287

In November 2007, the Fund
acquired a 4.0% working interest in the exploratory project South Timbalier 287
from GOM Shelf LLC (Apache Corporation) (Apache), the operator. South
Timbalier 287 is located southwest of the Mississippi River Delta in about 480
feet of water. This project began drilling in March 2008 and results are
expected in August 2008. Through June 30, 2008, the Fund has spent $2.3 million
related to this property, for which the total estimated budget is $2.6 million.

Successful Projects

Liberty Project

In
April 2008, the Fund acquired a 5.0% working interest in the Liberty Project,
an exploratory project operated by LLOG Exploration Offshore, Inc. (LLOG).
This project began drilling in May 2008 and was determined to be a success on
July 4, 2008. Completion efforts are ongoing and production is expected in the
second quarter 2009. Through June 30, 2008, the Fund has spent $2.4 million on
this well, for which the total estimated budget is $4.3 million.

South Pelto 9

In July 2006, the Fund
acquired a 16.67% working interest from Newfield Exploration Company
(Newfield), the operator. South Pelto 9 was deemed successful in late-2006
and production commenced in September 2007. In August 2007, Newfield sold its
interest in this property to McMoRan Exploration Co. (McMoRan). At that time,
McMoRan assumed Newfields responsibilities as the operator of this property.
The Fund has spent $5.6 million related to this property.

Eugene Island
346/347

Well #1

In March 2007, the Fund
acquired a 5.0% working interest in the exploratory project Eugene Island
346/347 from Newfield, the operator. In June 2007, the well was deemed
successful. In August 2007, Newfield sold its interest in this property to
McMoRan Exploration Co. (McMoRan). At that time, McMoRan assumed Newfields
responsibilities as the operator of this property. The well was completed and
production commenced in June 2008. The Fund has spent $3.5 million related to
this well.

Well #2

As a result of the drilling
success of the first exploratory well for Eugene Island 346/347, the second and
third wells commenced drilling in May 2008. In late-May 2008, Eugene Island
346/347 well #2 was determined to be successful and production commenced in
July 2008. Through June 30, 2008, the Fund has spent $0.6 million related to
this well.

Dry Holes

Eugene Island
346/347 Well #3

In June 2008, the Fund was
informed by McMoRan that Eugene Island 346/347 well #3 did not have
commercially productive quantities of either natural gas or oil and had been
deemed an unsuccessful well, or dry hole. As a result of this dry hole, the Fund recorded dry-hole costs of $0.3
million during the six months ended June 30, 2008.

Walker Ridge 155

In 2007 the Fund acquired a
1.0% working interest in the exploratory project Walker Ridge 155 from
Kerr-McGee Oil & Gas Corporation (Kerr McGee), a wholly owned subsidiary
of Anadarko Petroleum Corporation (Anadarko), the operator of the project.
Drilling for Walker Ridge 155, a deepwater project began in mid-August 2007.

On June 3, 2008, the Fund
was informed by Anadarko that based upon its evaluation of the
three-dimensional data surrounding the Walker Ridge 155 lease block, they have
elected not to continue drilling this well. The well has been determined to be
unsuccessful, or a dry hole, and has been plugged and abandoned. Dry-hole costs
related to this well, including plug and abandonment expenses, for the six
months ended June 30, 2008 were $2.2 million.

12

---



High Island 38

In
the fourth quarter 2007, the Fund acquired a 12.5% working interest in the High
Island 38 project, which is operated by W&T Offshore, Inc. (W&T
Offshore). In June 2008, the
well was determined to be unsuccessful, or a dry hole, and has been plugged and
abandoned. Dry-hole costs related to this well, including plug and abandonment
expenses, for the six months ended June 30, 2008 were $6.4 million.

South Marsh Island 213

In
March 2008, the Fund acquired a 5.5% working interest in the exploratory
project South Marsh Island 213 from LLOG, the operator. This project began
drilling in March 2008. On April 30, 2008 the Fund was informed by LLOG that
the well being drilled on the South Marsh Island 213 lease block did not have
commercially productive quantities of either natural gas or oil and had been
deemed an unsuccessful well, or dry hole. Dry-hole costs related to this well, including plug and abandonment
expenses, for the six months ended June 30, 2008 were $1.7 million.

Results of Operations

The following review of
operations for the three and six months ended June 30, 2008 and 2007 should be
read in conjunction with the Funds financial statements and the notes thereto.

|                                      |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|------------------------------------- |  | --------------------------- | ------ | ------------------------- | - | ------ | - | ---- | ------ | - | - | ------ | -
|                                      |  | Three months ended June 30, |        | Six months ended June 30, |  
|                                      |  | 2008                        |        | 2007                      |   | 2008   |   | 2007 |       
|                                      |  |                             |        |                           |   |        |   |      |       
|                                      |  | (in thousands)              |       
|Revenue                               |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Oil and gas
  revenue                 |  | $                           | 4,046  |                           | $ |       |   | $    | 6,461  |   | $ |       |  
|                                     
|Expenses                              |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Depletion and
  amortization          |  |                             | 1,349  |                           |   |       |   |      | 2,169  |   |   |       |  
|Dry-hole costs                        |  |                             | 9,857  |                           |   | 5      |   |      | 10,281 |   |   | 1,855  |  
|Management
  fees to affiliate        |  |                             | 549    |                           |   | 587    |   |      | 1,101  |   |   | 1,174  |  
|Casualty loss                         |  |                             |       |                           |   | 3,468  |   |      |       |   |   | 3,468  |  
|Operating
  expenses                  |  |                             | 105    |                           |   | 39     |   |      | 137    |   |   | 40     |  
|General and
  administrative expenses |  |                             | 258    |                           |   | 138    |   |      | 457    |   |   | 234    |  
|                                      |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Total expenses                        |  |                             | 12,118 |                           |   | 4,237  |   |      | 14,145 |   |   | 6,771  |  
|                                      |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Loss from
  operations                |  |                             | (8,072 | )                         |   | (4,237 | ) |      | (7,684 | ) |   | (6,771 | )
|Other income                          |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Interest
  income                     |  |                             | 180    |                           |   | 658    |   |      | 616    |   |   | 1,372  |  
|                                      |  |                             |        |                           |   |        |   |      |        |   |   |        |  
|Net loss                              |  | $                           | (7,892 | )                         | $ | (3,579 | ) | $    | (7,068 | ) | $ | (5,399 | )
|                                      |  |                             |        |                           |   |        |   |      |        |   |   |        |  

Oil and Gas Revenue. The Fund has had two wells come onto
production, South Pelto 9 in September 2007 and Eugene Island 346/347 well #1
in June 2008. Oil and gas revenue for the three and six months ended June 30,
2008 were $4.0 million and $6.5 million, respectively. Prior to September 2007,
the Fund earned no operating revenues and was classified as an exploratory
stage enterprise.

During the three months
ended June 30, 2008, South Pelto 9 produced approximately 8,500 barrels of oil
and approximately 223 thousand mcf of natural gas and Eugene Island 346/347
well #1 produced approximately 941 barrels of oil and approximately 9 thousand
mcf of natural gas.

During the three months
ended June 30, 2008, the Funds oil prices have averaged $122 per barrel and
natural gas prices have averaged $13.12 per mcf.

During the six months ended
June 30, 2008, South Pelto 9 produced 15,800 barrels of oil and approximately
368 thousand mcf of natural gas and Eugene Island 346/347 well #1 produced
approximately 941 barrels of oil and approximately 9 thousand mcf of natural
gas.

During the six months ended
June 30, 2008, the Funds oil prices have averaged $111 per barrel and natural
gas prices have averaged $11.93 per mcf.

Depletion and
Amortization. For
the three and six months ended June 30, 2008, depletion and amortization was
$1.3 million and $2.2 million, respectively. The Funds producing wells, South
Pelto 9 and Eugene Island 346/347 well #1, began production in September 2007
and June 2008, respectively. Prior to that time, the Fund did not have
production and therefore did not have depletion and amortization expense.

13

---



Dry-hole Costs. Dry-hole costs are those costs incurred to
drill and develop a well that is ultimately found to be incapable of producing
either oil or natural gas in sufficient quantities to justify completion of the
well. The following table summarizes dry-hole costs inclusive of plug and
abandonment costs. During the three and six months ended June 30, 2008, certain
wells received credits from their respective operators upon review and audit of
the wells costs.

|                                |  |                             |       |                           |   |      |   |      |        |   |   |       | 
|------------------------------- |  | --------------------------- | ----- | ------------------------- | - | ---- | - | ---- | ------ | - | - | ----- | 
|                                |  | Three months ended June 30, |       | Six months ended June 30, |  
|Lease Block                     |  | 2008                        |       | 2007                      |   | 2008 |   | 2007 |       
|                                |  |                             |       |                           |   |      |   |      |       
|                                |  | (in thousands)              |      
|High Island 38                  |  | $                           | 6,406 |                           | $ |     |   | $    | 6,406  |   | $ |      | 
|Walker Ridge
  155              |  |                             | 2,246 |                           |   |     |   |      | 2,246  |   |   |      | 
|South Marsh
  Island 213        |  |                             | 1,251 |                           |   |     |   |      | 1,688  |   |   |      | 
|Eugene Island
  346/347 well #3 |  |                             | 275   |                           |   |     |   |      | 275    |   |   |      | 
|West Delta 95                   |  |                             | (320  | )                         |   | 11   |   |      | (334   | ) |   | 1,836 | 
|Other wells                     |  |                             | (1    | )                         |   | (6   | ) |      |       |   |   | 19    | 
|                                |  |                             |       |                           |   |      |   |      |        |   |   |       | 
|                                |  | $                           | 9,857 |                           | $ | 5    |   | $    | 10,281 |   | $ | 1,855 | 
|                                |  |                             |       |                           |   |      |   |      |        |   |   |       | 

Management Fees
to Affiliate. For the three months ended June 30, 2008 and
2007, the Fund incurred management fees of $0.5 million and $0.6 million,
respectively, representing 2.5% of total capital contributions, net of
cumulative dry-hole and related well costs incurred by the Fund. The Fund
incurred $1.1 million and $1.2 million for the six months ended June 30, 2008
and 2007, respectively. The management fee, payable monthly to the Manager, is
for expenses associated with overhead incurred by the Manager for its ongoing
management, administrative and advisory services. Such overhead expenses
include but are not limited to rent, payroll and benefits for employees of the
Manager, and other administrative costs.

Casualty Loss. For the
three and six months ended June 30, 2007, the Fund recorded casualty losses of
$3.5 million related to West Delta 95 and West Cameron 78/95 insurance claims.
There was no casualty loss recorded during the three and six months ended June
30, 2008.

Operating
Expenses. Operating expenses represent the costs of operating and maintaining wells and
related facilities, geological costs and accretion expense. For each of the
three and six months ended June 30, 2008, operating expenses were $0.1 million
attributable to the onset of production and accretion expense for South Pelto 9
and Eugene Island 346/347 well #1. For the three and six months ended June 30,
2007, operating expenses were $39 thousand and $40 thousand, respectively,
attributable to geological costs.

General and
Administrative Expenses. General and administrative expenses represent
costs specifically identifiable or allocable to the Fund, as detailed in the
schedule below.

|                       |  |                             |     |                           |   |      |  |      |     |  |   |     | 
|---------------------- |  | --------------------------- | --- | ------------------------- | - | ---- |  | ---- | --- |  | - | --- | 
|                       |  | Three months ended June 30, |     | Six months ended June 30, |  
|                       |  | 2008                        |     | 2007                      |   | 2008 |  | 2007 |    
|                       |  |                             |     |                           |   |      |  |      |    
|                       |  | (in thousands)              |    
|Insurance              |  | $                           | 139 |                           | $ | 56   |  | $    | 257 |  | $ | 71  | 
|Accounting
  fees      |  |                             | 96  |                           |   | 57   |  |      | 151 |  |   | 111 | 
|Trust fees and
  other |  |                             | 23  |                           |   | 25   |  |      | 49  |  |   | 52  | 
|                       |  |                             |     |                           |   |      |  |      |     |  |   |     | 
|                       |  | $                           | 258 |                           | $ | 138  |  | $    | 457 |  | $ | 234 | 
|                       |  |                             |     |                           |   |      |  |      |     |  |   |     | 

Insurance expense represents
premiums related to well control insurance, which varies dependent upon
drilling activity, and directors and officers liability policy, which is
allocated by the Manager to the Fund based on capital raised by the Fund to
total capital raised by all oil and natural gas funds managed by the Manager.
Accounting fees represent annual audit and tax preparation fees, quarterly
reviews and filing fees of the Fund. Trust fees represent bank fees associated
with the management of the Funds cash accounts.

Interest Income. Interest
income is comprised of interest earned on money market accounts and investments
in U.S. Treasury securities. For the three months ended June 30, 2008, interest
income was $0.2 million, a $0.5 million decrease from the three months ended
June 30, 2007. For the six months ended June 30, 2008, interest income was $0.6
million, a $0.8 million decrease from the six months ended June 30, 2007. The
decreases were attributable to a reduction in interest rates during the three
and six months ended June 30, 2008 coupled with a decrease in average
outstanding balances earning interest due to capital expenditures during the
period.

14

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Capital Resources and Liquidity

Operating Cash FlowsCash flows provided by operating activities for
the six months ended June 30, 2008 were $2.5 million principally attributable
to revenue receipts of $5.4 million, interest income received of $0.2 million
and favorable working capital of $0.1 million. These amounts were partially
offset by management fees of $1.1 million, MMS prepayments for estimated
potential royalties totaling $0.9 million, payments to affiliates of $0.7
million for amounts outstanding at December 31, 2007, general and
administrative expenses of $0.5 million and operating expenses of $0.1 million.

Cash flows
used in operating activities for the six months ended June 30, 2007 were $1.0
million. Management fees and general and administrative and other expenses of
$1.2 million and $0.3 million, respectively, were offset by interest income
received of $0.5 million.

Investing Cash FlowsCash flows provided by investing activities for
the six months ended June 30, 2008 were $3.1 million related to proceeds from
the maturity of U.S. Treasury securities totaling $40.9 million, partially
offset by $28.0 million reinvested in marketable securities and capital
expenditures for oil and gas properties totaling $9.8 million, inclusive of
advances. Additionally, in the six months ended June 30, 2008, the Fund
increased its salvage fund investments by $16 thousand, which consisted of the
interest earned on this account.

Cash flows
used in investing activities for the six months ended June 30, 2007 were $8.4
million, related to capital expenditures for oil and gas properties of $8.7
million and investments in marketable securities, inclusive of salvage fund, of
$25.3 million, partially offset by proceeds from the maturity of US Treasury
Notes of $25.6 million.

Financing Cash FlowsCash flows used in financing activities were $2.7
million for six months ended June 30, 2008 related to the payment of manager
and shareholder distributions.

There were no
cash flows related to financing activities for the six months ended June 30,
2007.

Estimated Capital Expenditures

The Fund has
entered into multiple offshore operating agreements for the drilling and
development of its investment properties. The estimated capital expenditures
associated with these agreements can vary depending on the stage of development
on a property-by-property basis. As of June 30, 2008, the Fund had commitments
related to participation agreements totaling $3.8 million for properties.

When the
Manager makes a decision for participation in a particular project, it assumes
that the well will be successful and allocates enough capital to budget for the
completion of that well and the additional development wells and infrastructure
anticipated. If the exploratory well is deemed a dry-hole or if it is
un-economical, the capital allocated to the completion of that well and to the
development of additional wells is then reallocated to a new project or used to
make additional investments.

Liquidity Needs

The Funds
primary short-term liquidity needs are to fund its operations, including
management fees and capital expenditures, with existing cash on-hand and income
earned from its short-term investments and cash and cash equivalents. The
Manager is entitled to receive an annual management fee from the Fund
regardless of whether the Fund is profitable in that year. The annual fee,
payable monthly, is equal to 2.5% of total capital contributed by shareholders,
net of cumulative dry-hole and related well costs incurred.

With respect
to the payment of management fees, until one of the Funds projects begins
producing, all or a portion of the management fee is paid generally from the
interest or dividend income generated by the Funds development capital that
has not been spent, although the management fee can be paid out of capital
contributions. Such interest and/or dividend income is expected to be
sufficient to cover Fund expenses, including the management fee. However in
periods of declining interest rates, and as the Fund expends its capital on
projects, interest and/or dividend income may not be sufficient, which would
require the Fund to use capital contributions to fund such expenses. Generally,
it can take anywhere from 18 to 24 months to bring a project to production.
Once a well is on production, the management fee and fund expenses are paid
from operating income. Although the management fee can be paid out of capital
contributions, this is not the Funds intent.

15

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Distributions
are funded from cash flow from operations, and the frequency and amount are
within the Managers discretion subject to available cash from operations,
reserve requirements and Fund operations.

The capital
raised by the Fund in its private placement is more than likely all the capital
it will be able to obtain for investments in projects. The number of projects
in which the Fund can invest will naturally be limited and each unsuccessful
project the Fund experiences, if any, will not only reduce its ability to
generate revenue, but also exhaust its limited supply of capital. Typically,
the Manager seeks an investment portfolio that combines high and low risk
exploratory projects.

Suspension of MMS
Royalty Relief

Under Mineral
Management Services (MMS) rules, the Fund is eligible for annual royalty
relief provided that the average New York Mercantile Exchange (NYMEX) sales
price for shallow water, deep natural gas (Average NYMEX Price) does not
exceed price thresholds established by the MMS, which will be published during
the first quarter of 2009. The Average NYMEX Price during the six months ended
June 30, 2008 was $10.10. Based upon current estimations of the 2008 price
threshold by the MMS, in the event the Average NYMEX Price exceeds $10.68 for
the second half of 2008, royalty relief would be suspended and the Fund would
be obligated to pay its previously relieved MMS royalties. In addition, the
Funds future reserve estimates report for natural gas would be reduced by
16.67%. The reduction in revenues resulting from an obligation to pay these
royalties and subsequent reduction of proved reserves could have a material
adverse effect on the Funds results of operations. If the Average NYMEX Price
is below the threshold established by the MMS, the Fund would not have an
obligation to pay royalties for those properties which qualify for royalty
relief and the reserve balances would not be reduced. With regard to the
shallow water, deep natural gas properties, there was no reduction in reserves
for potential future royalties as of December 31, 2007 as a result of the
average 2007 NYMEX price for gas being below the price threshold.

The Funds
natural gas revenues for the six months ended June 30, 2008 would be reduced by
$0.7 million if the 2008 annual Average NYMEX Price ultimately exceeds the
price threshold established by the MMS. At June 30, 2008, the Fund has not
recorded a liability associated with this contingency, based upon the Managers
assessment of its probability; however, the Fund has prepaid the MMS this
amount to avoid the incurrence of potential interest charges.

Off-Balance Sheet Arrangements

The Fund had
no off-balance sheet arrangements as of June 30, 2008 and December 31, 2007 and
does not anticipate the use of such arrangements in the future.

Contractual Obligations

The Fund
enters into operating agreements with Operators. On behalf of the Fund, an
Operator enters into various contractual commitments pertaining to exploration,
development and production activities. The Fund does not discuss or negotiate
any such contracts. No contractual obligations exist at June 30, 2008 and
December 31, 2007 other than those discussed in Estimated Capital
Expenditures above.

ITEM 3. QUANTITATIVE AND QUALITATIVE
DISCLOSURES ABOUT MARKET RISK

Not required.

ITEM 4. CONTROLS AND PROCEDURES

In accordance
with Exchange Act Rules 13a-15 and 15d-15, the Fund carried out an evaluation,
under the supervision and with the participation of management, including its
Chief Executive Officer and Chief Financial Officer, of the effectiveness of
our disclosure controls and procedures as of the end of the period covered by
this report. Based on that evaluation, our Chief Executive Officer and Chief
Financial Officer concluded that the Funds disclosure controls and procedures
were effective as of June 30, 2008.

16

---



There has been
no change in the Funds internal control over financial reporting that occurred
during the three months ended June 30, 2008 that has materially affected, or is
reasonably likely to materially affect, the Funds internal control over
financial reporting.

PART II. OTHER INFORMATION

ITEM 1. LEGAL PROCEEDINGS

There have
been no changes to the legal proceedings disclosed in the Funds most recent
Annual Report on Form 10-K.

ITEM 1A. RISK FACTORS

Not required.

ITEM 2. UNREGISTERED SALES OF EQUITY
SECURITIES AND USE OF PROCEEDS

None.

ITEM 3. DEFAULTS UPON SENIOR SECURITIES

None.

ITEM 4. SUBMISSIONS OF MATTERS TO A VOTE OF
SECURITY HOLDERS

None.

ITEM 5. OTHER INFORMATION

None.

ITEM 6. EXHIBITS

|                 |  |                                                                                                                                                                                                                                                                 
|---------------- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|EXHIBIT
  NUMBER |  | TITLE OF EXHIBIT                                                                                                                                                                                                                                                
|                 |  |                                                                                                                                                                                                                                                                 
|10.1             |  | Participation
  Agreement between El Paso E&P Company, L.P. and Ridgewood Energy Corporation
  as Manager and LLOG Exploration Offshore, Inc. for South Marsh Island Block
  213. (previously filed)                                                            
|                 |  |                                                                                                                                                                                                                                                                 
|10.2             |  | Participation
  Agreement between LLOG Exploration Offshore, Inc. and Ridgewood Energy
  Corporation as Manager for Liberty Project.                                                                                                                            
|                 |  |                                                                                                                                                                                                                                                                 
|10.3             |  | Participation
  Agreement between PetroQuest Energy, L.L.C. and Ridgewood Energy Corporation
  as Manager for Ruby Project.                                                                                                                                     
|                 |  |                                                                                                                                                                                                                                                                 
|31.1             |  | Certification
  of Robert E. Swanson, Chief Executive Officer, pursuant to Securities
  Exchange Act Rule 13a-14(a).                                                                                                                                            
|                 |  |                                                                                                                                                                                                                                                                 
|31.2             |  | Certification of Kathleen P. McSherry,
  Chief Financial Officer, pursuant to Securities Exchange Act Rule 13a-14(a).                                                                                                                                           
|                 |  |                                                                                                                                                                                                                                                                 
|32               |  | Certifications
  pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of The
  Sarbanes-Oxley Act of 2002, signed by Robert E. Swanson, Chief Executive
  Officer of the Fund and Kathleen P. McSherry, Chief Financial Officer of the
  Fund.

17

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SIGNATURES

Pursuant to
the requirements of the Securities Exchange Act of 1934, the Registrant has
caused this report to be signed on its behalf by the undersigned, thereunto
duly authorized.

|                      |  |     |        |  |                                                       
|--------------------- |  | --- | ------ |  | ------------------------------------------------------
|Dated: August 1, 2008 |  |     |        |  | RIDGEWOOD
  ENERGY O FUND, LLC                        
|                      |  |     |        |  |                                                       
|                      |  | By: | /s/    |  | ROBERT E.
  SWANSON                                   
|                      |  |     |        |  |                                                       
|                      |  |     | Name:  |  | Robert E.
  Swanson                                   
|                      |  |     | Title: |  | President
  and Chief Executive Officer               
|                      |  |     |        |  | (Principal
  Executive Officer)                       
|                      |  |     |        |  |                                                       
|Dated: August 1, 2008 |  |     |        |  |                                                       
|                      |  | By: | /s/    |  | KATHLEEN P.
  McSHERRY                                
|                      |  |     |        |  |                                                       
|                      |  |     | Name:  |  | Kathleen P.
  McSherry                                
|                      |  |     | Title: |  | Executive
  Vice President and Chief Financial Officer
|                      |  |     |        |  | (Principal
  Financial and Accounting Officer)        

18

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