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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549



FORM 40-F



| |  ̈ | REGISTRATION STATEMENT PURSUANT TO
SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934
| | - | ------------------------------------------------------------------------------------

OR

| | þ | ANNUAL REPORT PURSUANT TO SECTION 13(a) OR 15(d) OF
THE SECURITIES EXCHANGE ACT OF 1934
| | - | ---------------------------------------------------------------------------------------



For the fiscal year ended: December 31,
2012               Commission File Number: 001-34406



|ADVANTAGE OIL & GAS LTD.                                                      
|------------------------------------------------------------------------------
|(Exact name of Registrant as specified in its charter)                        
|                                                                              
|N/A                                                                           
|(Translation of Registrant’s name into English (if applicable))               
|                                                                              
|ALBERTA                                                                       
|(Province or other jurisdiction of incorporation or organization)             
|                                                                              
|1311                                                                          
|(Primary Standard Industrial Classification Code Number (if applicable))      
|                                                                              
|N/A                                                                           
|(I.R.S. Employer Identification Number (if applicable))                       
|                                                                              
|Suite 700, 400 – 3 Avenue SW, Calgary, Alberta T2P 4H2 (403) 718-8000         
|(Address and telephone number of Registrant’s principal executive offices)    
|                                                                              
|Corporation Service Company                                                   
|                                                                              
|1133 Avenue of Americas, 31st Floor, New York, NY 10036 1-800-927-9800        
|(Name, address (including zip code) and telephone number (including area code)
|of agent for service in the United States)                                    



Securities registered or to be registered pursuant to Section
12(b) of the Act.



|Title of each class   |  | Name of each exchange on which registered
|--------------------- |  | -----------------------------------------
|                      |  |                                          
|Common
        Shares |  | New
        York Stock Exchange          



Securities registered or to be registered pursuant to Section
12(g) of the Act.



|None
        (Title of Class)
|-----------------------------



Securities for which there is a reporting obligation pursuant
to Section 15(d) of the Act.

|None
        (Title of Class)
|-----------------------------



|SEC 2285 (01-12) | Persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.
|---------------- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------



For annual reports, indicate by check mark the information filed
with this Form:



þAnnual
information form               þAudited
annual financial statements



Indicate the number of outstanding shares
of each of the issuer’s classes of capital or common stock as of the close of the period covered by the annual report.



Common Shares: 168,382,838



Indicate by check mark whether the Registrant
(1) has filed all reports required to be filed by Section 13 or 15(d) of the Exchange Act 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 þ               No
 ̈



Indicate by check mark whether the Registrant
has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted
and posted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for
such shorter period that the Registrant was required to submit and post such files).



Yes  ̈
               No  ̈











DOCUMENTS INCLUDED IN THIS FORM



The following documents
are included in the Form:



|No. | Document                                                                                                                                                                                                                                                                                 
|--- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|    |                                                                                                                                                                                                                                                                                          
|1.  | Annual Information Form of the Registrant for the year ended December 31, 2012 (filed herein as Exhibit 99.1)                                                                                                                                                                            
|    |                                                                                                                                                                                                                                                                                          
|2.  | Consolidated Financial Statements of the Registrant for the fiscal year ended December 31, 2012, prepared under International Financial Reporting Standards as issued by the International Accounting Standards Board (filed herein as Exhibit 99.2)                                     
|    |                                                                                                                                                                                                                                                                                          
|3.  | Consolidated Management’s Discussion and Analysis of the Registrant for the fiscal year ended December 31, 2012 (filed herein as Exhibit 99.3).                                                                                                                                          
|    |                                                                                                                                                                                                                                                                                          
|4.  | Consent of PricewaterhouseCoopers LLP to the inclusion of the Auditors’ Report dated March 25, 2013
on the Registrant’s Audited Consolidated Financial Statements for the fiscal year ended December 31, 2012.                                                                           
|    |                                                                                                                                                                                                                                                                                          
|5.  | Consent of Sproule Associated Limited to the incorporation by reference herein of its Statement of Reserves
Data and other Information in Form 51-101F1, which statement and report is contained in the Registrant’s Annual Information
Form for the fiscal year ended December 31, 2012.
|    |                                                                                                                                                                                                                                                                                          
|6.  | CEO Certification pursuant to rule 13a-14(a) of the Exchange Act.                                                                                                                                                                                                                        
|    |                                                                                                                                                                                                                                                                                          
|7.  | CFO Certification pursuant to rule 13a-14(a) of the Exchange Act.                                                                                                                                                                                                                        
|    |                                                                                                                                                                                                                                                                                          
|8.  | CEO Certification pursuant to U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.                                                                                                                                                                 
|    |                                                                                                                                                                                                                                                                                          
|9.  | CFO Certification pursuant to U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.                                                                                                                                                                 











PRINCIPAL DOCUMENTS



A.           Annual
Information Form



For the Annual Information
Form for the fiscal year ended December 31, 2012, see Exhibit 99.1 included herein.



B.           Audited
Annual Financial Statements



For consolidated audited
financial statements, including the report of independent chartered accountants with respect thereto, see the Consolidated Financial
Statements of the Registrant for the fiscal year ended December 31, 2012, included as Exhibit 99.2 herein.



C.           Consolidated
Management’s Discussion and Analysis



For
consolidated management’s discussion and analysis, see Consolidated Management’s Discussion and Analysis of the
Registrant for the fiscal year ended December 31, 2012, included as Exhibit 99.3 herein.



CERTIFICATIONS AND DISCLOSURES REGARDING
CONTROLS AND PROCEDURES



A.           CERTIFICATIONS.
See Exhibits 31.1 and 31.2 to this Annual Report on Form 40-F.



B.           DISCLOSURE
CONTROLS AND PROCEDURES. As of the end of the Registrant’s fiscal year ended December 31, 2012, an evaluation of the effectiveness
of the Registrant’s “disclosure controls and procedures” (as such term is defined in Rules 13a-15(e) and 15d-15(e)
of the Securities Exchange Act of 1934, as amended (the “Exchange Act”)) was carried out by the Registrant’s
management with the participation of the principal executive officer and principal financial officer. Based upon that evaluation,
the Registrant’s principal executive officer and principal financial officer have concluded that as of the end of that fiscal
year, the Registrant’s disclosure controls and procedures are effective to ensure that information required to be disclosed
by the Registrant in reports that it files or submits under the Exchange Act is (i) recorded, processed, summarized and reported
within the time periods specified in Securities and Exchange Commission rules and forms and (ii) accumulated and communicated to
the Registrant’s management, including its principal executive officer and principal financial officer, to allow timely decisions
regarding required disclosure.



It should be noted
that while the Registrant’s principal executive officer and principal financial officer believe that the
Registrant’s disclosure controls and procedures provide a reasonable level of assurance that they are effective, they
do not expect that the Registrant’s disclosure controls and procedures or internal control over financial reporting
will prevent all errors and fraud. A control system, no matter how well conceived or operated, can provide only reasonable,
not absolute, assurance that the objectives of the control system are met. Reference is made in the “Controls and
Procedures” and “Evaluation of Disclosure Controls and Procedures” sections of Consolidated
Management’s Discussion and Analysis of the Registrant for the fiscal year ended December 31, 2012, included
herein.











C.           MANAGEMENT’S
ANNUAL REPORT ON INTERNAL CONTROL OVER FINANCIAL REPORTING. The required disclosure is included in “Management’s Report
on Internal Control over Financial Reporting” that accompanies the Registrant’s Consolidated
Financial Statements for the fiscal year ended December 31, 2012, filed as part of this Annual Report on Form 40-F.



D.           ATTESTATION
REPORT OF THE REGISTERED PUBLIC ACCOUNTING FIRM. The required disclosure is included in the “Independent Auditor’s Report” that accompanies the Registrant’s Consolidated Financial Statements for the fiscal year ended
December 31, 2012, filed as part of this Annual Report on Form 40-F.



E.           CHANGES
IN INTERNAL CONTROL OVER FINANCIAL REPORTING. During the fiscal year ended December 31, 2012, there were no significant changes
in the Registrant’s internal control over financial reporting that have materially affected, or are reasonably likely to
materially affect, the Registrant’s internal control over financial reporting. Reference is made in the “Controls and
Procedures” section of Management’s Discussion and Analysis of the Registrant for the fiscal year ended December 31,
2012, included herein.



NOTICES PURSUANT TO REGULATION BTR



None.



CODE OF ETHICS FOR CHIEF EXECUTIVE
OFFICER
AND SENIOR FINANCIAL OFFICERS





The Registrant has adopted
a Code of Ethics for its senior officers, principal financial officer and controller or principal accounting officer, directors
and employees. This code applies to the President and Chief Executive Officer, Chief Financial Officer, Senior Vice President,
the Vice President, Finance, Vice President Exploitations, Directors and employees. It is available on the Registrant’s
web site at www.advantageog.com and in print to any shareholder who requests it. All amendments to the code, and all waivers
of the code with respect to any of the officers covered by it, will be posted on the Registrant’s web site and provided
in print to any shareholder who requests them.





AUDIT COMMITTEE



Identification of Audit Committee





The following individuals
comprise the entire membership of the Advantage Audit Committee: Paul Haggis, Ronald McIntosh and Stephen Balog.



Audit Committee Financial Experts



Paul G. Haggis has been
determined by the board of the Registrant to meet the “audit committee financial expert” criteria prescribed by the
Securities and Exchange Commission and has been designated as audit committee financial expert for the Audit Committee of the board
of the Registrant.



Each of the directors
serving on the Audit Committee has also been determined by the board of the Registrant to be independent within the criteria established
by the New York Stock Exchange, Inc. for audit committee membership.











PRINCIPAL ACCOUNTING
FEES ANDSERVICES – INDEPENDENT AUDITORS





Fees payable to the Registrant’s
independent auditors for the years ended December 31, 2012 and December 31, 2011, totaled $612,000 and $526,000, respectively,
as detailed in the following tables. All funds are in Canadian dollars.





The following table discloses
fees billed to the Registrant by its current auditors, PricewaterhouseCoopers LLP:



|                   |  | Year ended December 31, 2012 |         |  | Year ended December 31, 2011 |  
|------------------ |  | ---------------------------- | ------- |  | ---------------------------- | -
|Audit Fees         |  | $                            | 576,000 |  |                              | $
|Audit Related Fees |  | $                            | 36,000  |  |                              | $
|Tax Fees           |  | $                            | 0       |  |                              | $
|All Other Fees     |  | $                            | 0       |  |                              | $
|TOTAL              |  | $                            | 612,000 |  |                              | $



The nature of the services provided by
the Registrant’s independent auditors under each of the categories indicated in the table is described below.



Audit Fees



Audit fees were for professional services
rendered by the Registrant’s independent auditors for the audit of the Registrant’s annual financial statements and
services provided in connection with statutory and regulatory filings or engagements. These services include audit or review of
financials forming part of such prospectus.



Audit-Related Fees



Audit-related fees were for assurance and
related services reasonably related to the performance of the audit or review of the annual statements and are not reported under
“Audit Fees” above. These services include work related to Secondary Offering in 2012 and work related to prospectus for the Longview transaction
and French translation in 2011.



Tax Fees



Tax fees were for tax advice and tax planning
professional services. These services consisted of general tax planning and advisory services relating to common forms of domestic
and international taxation (i.e., income tax, capital tax, goods and services tax).



All Other Fees



None.











PREAPPROVAL POLICIES AND PROCEDURES



In 2012 Advantage’s
Audit Committee pre-approved all audit, audit-related and tax fees. The Audit Committee will be informed routinely as to the non-audit
services actually provided by the auditor pursuant to this pre-approval process. The auditors also present the estimate for the
annual audit related services to the Audit Committee for approval prior to undertaking the annual audit of the financial statements.



OFF-BALANCE SHEET ARRANGEMENTS



None.

CONTRACTUAL OBLIGATIONS











|                              |  | Payments due by period (Cdn$MM) |      
|----------------------------- |  | ------------------------------- | -----
|                              |  |                                 |      
|                              |  | Total                           |      
|Building Leases               |  | $                               | 4.1  
|Pipeline/Transportation       |  | $                               | 26.0 
|Bank Indebtedness(1)          |  | $                               | 293.9
|Convertible Debenture(2)      |  | $                               | 97.0 
|Total Contractual Obligations |  | $                               | 421.0





| | (1) | The Corporation’s bank indebtedness does not have
specific maturity dates. It is governed by credit facility agreements with a syndicate of financial institutions. Under the terms
of the agreements, the facilities are reviewed annually, with the next reviews scheduled in June 2013. The facilities
are revolving, and extendible at each annual review for a further 364 day period at the option of the syndicate. If not extended,
the credit facilities are converted at that time into one-year term facilities, with the principal payable at the end of such
one-year terms. Management fully expects that the facilities will be extended at each annual review.
| | --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (2) | As at December 31, 2012, Advantage had $86.2 million
convertible debentures outstanding. The convertible debentures are convertible to common shares based on an established conversion
price. All remaining obligations related to convertible debentures can be settled through the payment of cash or issuance of common
shares at Advantage’s option.
| | --- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



DISCLOSURES PURSUANT TO REQUIREMENTS
OF THE
NEW YORK STOCK EXCHANGE



Presiding Director at Meetings of Non-Management Directors



The Registrant schedules
regular executive sessions in which the Registrant’s “non-management directors” (as that term is defined in the
rules of the New York Stock Exchange) meet without management participation. Steven Sharpe serves as the presiding director (the
“Chair of the Board”) at such sessions. Each of the Registrant’s non-management directors is “independent”
as such term is used in the rules of the Canadian Securities Commissions and the New York Stock Exchange Corporate Governance Standards.











Communication with Non-Management Directors



Shareholders may send
communications to the Registrant’s non-management directors by writing to Investors Relations, Canterra Tower, Suite 700,
400 - 3 Avenue SW, Calgary, Alberta T2P 4H2, or calling the toll free number at 1-866-393-0393. Communications will be referred
to the Chair of the Board for appropriate action. The status of all outstanding concerns addressed to the Chair of the Board will
be reported to the board of directors as appropriate.



Corporate Governance Guidelines



According to NYSE Rule
303A.09, a listed company must adopt and disclose a set of corporate governance guidelines with respect to specified topics and
must disclose any significant ways in which its practices differ from those followed by US domestic companies under the NYSE rules.
Such guidelines and disclosures are required to be posted on the listed company’s website. The Registrant has adopted the
required guidelines and made the required disclosures, all of which are available on the Registrant’s website at www.advantageog.com
and in print to any shareholder who requests them.



Board Committee Charters



Advantage’s
Audit Committee Charter, the Terms of Reference of the Human Resources, Compensation and Corporate Governance Committee and the
Terms of Reference for the Independent Reserve Evaluation Committee are available for viewing on the Registrant’s website
at www.advantageog.com and are available in print to any person who requests them. Requests for copies of these documents
should be made by contacting: Investor Relations, Canterra Tower, Suite 700, 400 - 3 Avenue SW, Calgary, Alberta T2P 4H2.



UNDERTAKING



The Registrant undertakes
to make available, in person or by telephone, representatives to respond to inquiries made by the Commission staff, and to furnish
promptly, when requested to do so by the Commission staff, information relating to: the securities registered pursuant to Form 40-F;
the securities in relation to which the obligation to file an annual report on Form 40-F arises; or transactions in said securities.



CONSENT TO SERVICE OF PROCESS



The Registrant has previously
filed with the Commission a Form F-X in connection with the Common Shares.



Any change to the name
or address of the agent for service of process of the Registrant shall be communicated promptly to the Securities and Exchange
Commission by an amendment to the Form F-X referencing the file number of the relevant registration statement.











EXHIBITS



The following exhibits
are filed as part of this report.



|ExhibitNumber |  | Description                                                                                                                                                                                                                                                                              
|------------- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|              |  |                                                                                                                                                                                                                                                                                          
|23.1          |  | Consent of PricewaterhouseCoopers LLP to the inclusion of the Auditors’ Report dated March 25, 2013
on the Registrant’s Audited Consolidated Financial Statements for the fiscal year ended December 31, 2012.                                                                           
|              |  |                                                                                                                                                                                                                                                                                          
|23.2          |  | Consent of Sproule Associated Limited to the incorporation by reference herein of its Statement of Reserves Data and other Information in Form 51-101F1, which statement and report is contained in the Registrant’s Annual Information Form for the fiscal year ended December 31, 2012.
|              |  |                                                                                                                                                                                                                                                                                          
|31.1          |  | CEO Certification pursuant to rule 13a-14(a) of the Exchange Act.                                                                                                                                                                                                                        
|              |  |                                                                                                                                                                                                                                                                                          
|31.2          |  | CFO Certification pursuant to rule 13a-14(a) of the Exchange Act.                                                                                                                                                                                                                        
|              |  |                                                                                                                                                                                                                                                                                          
|32.1          |  | CEO Certification pursuant to U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.                                                                                                                                                                 
|              |  |                                                                                                                                                                                                                                                                                          
|32.2          |  | CFO Certification pursuant to U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.                                                                                                                                                                 
|              |  |                                                                                                                                                                                                                                                                                          
|99.1          |  | Annual Information Form of the Registrant for the year ended December 31, 2012.                                                                                                                                                                                                          
|              |  |                                                                                                                                                                                                                                                                                          
|99.2          |  | Consolidated Financial Statements of the Registrant for the fiscal year ended December 31, 2012, prepared under International Financial Reporting Standards as issued by the International Accounting Standards Board.                                                                   
|              |  |                                                                                                                                                                                                                                                                                          
|99.3          |  | Consolidated Management’s Discussion and Analysis of the Registrant for the fiscal year ended December 31, 2012.                                                                                                                                                                         











SIGNATURE



Pursuant to the requirements
of the Exchange Act, the Registrant certifies that it meets all of the requirements for filing on Form 40-F and has duly caused
this Annual Report on Form 40-F to be signed on its behalf by the undersigned, thereto duly authorized, in the City of Calgary,
Province of Alberta, Canada.



|Dated: March 26, 2013 |                         
|--------------------- | ------------------------
|                      |                         
|                      | ADVANTAGE OIL & GAS LTD.
|                      |                         
|                      | By:                     
|                      |                         
|                      |