<PAGE>   1
================================================================================

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

                                 ---------------

                                    FORM 10-K

(Mark One)

[X]  ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE
     ACT OF 1934 (FEE REQUIRED)
FOR THE FISCAL YEAR ENDED DECEMBER 31, 1997,

                                       OR

[ ]  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES
     EXCHANGE ACT OF 1934 (NO FEE REQUIRED)
For the transition period from               to
                               -------------    --------------
Commission file number 0-11672

                              HORIZON BANCORP, INC.
             (Exact name of registrant as specified in its charter)

       West Virginia                                 55-0631939
(State or other jurisdiction of                   (I.R.S. Employer
incorporation or organization)                    Identification No.)

     One Park Avenue, Beckley, WV                     25802-2803
(Address of principal executive offices)              (Zip Code)

                               (304) 255-7000
              (Registrant's telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

                               TITLE OF EACH CLASS
                                      None

                    NAME OF EACH EXCHANGE ON WHICH REGISTERED
                                      None

Securities registered pursuant to Section 12(g) of the Act:

                          COMMON STOCK PAR VALUE $1.00
                                (Title of Class)

     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
                                             -----   -----

     Indicate by check mark if disclosure of delinquent filers pursuant to Item
405 of Regulation S-K is not contained herein, and will not be contained, to the
best of the registrant's knowledge, in definitive proxy or information
statements incorporated by reference in Part III of this Form 10-K or any
amendment to this Form 10-K.

     As of March 5, 1998, there were 8,194,482 shares of Horizon Bancorp, Inc.
$1 par value common stock held by non-affiliates with an aggregate market value
of $237,639,980 based upon closing price on that day.

     As of March 5, 1998, there were 9,165,314 shares of Horizon Bancorp, Inc.
$1 par value common stock outstanding.
================================================================================


<PAGE>   2



                       DOCUMENTS INCORPORATED BY REFERENCE

<TABLE>
<CAPTION>
                                                                      INCORPORATED INTO
                                                                      -----------------
<S>                                                                    <C>
 (1) Portions of the Annual Report to Shareholders for
 the year ended December 31, 1997 (hereinafter the "1997
 Annual Report")....................................................    Parts I & II
 (2) Portions of the Definitive Proxy Statement for Annual Meeting
 of Shareholders to be held April 29, 1998, to be filed with the
 Securities Exchange Commission (the "Commission") .................    Part III
</TABLE>

                              HORIZON BANCORP, INC.
                                 FORM 10K INDEX

<TABLE>
<CAPTION>
                                                                                   PAGE
                                                                                   ----
<S>                <C>                                                             <C>
Part I        Item 1   Business                                                      1
              Item 2   Properties                                                    5
              Item 3   Legal Proceedings                                             5
              Item 4   Submission of Matters to a Vote of Security Holders           5

Part II       Item 5   Market for the Registrant's Common Stock and Related
                       Shareholder
                       Matters                                                       6
              Item 6   Selected Financial Data                                       6
              Item 7   Management's Discussion and Analysis of Financial
                       Condition and Results of Operations                           6
              Item 8   Financial Statements and Supplementary Data                   6
              Item 9   Changes in and Disagreements with Accountants on
                       Accounting and  Financial Disclosure                          6

Part III      Item 10  Directors and Executive Officers of the Registrant            6
              Item 11  Executive Compensation                                        6
              Item 12  Security Ownership of Certain Beneficial Owners and
                       Management                                                    6
              Item 13  Certain Relationships and Related Transactions                6

Part IV       Item 14  Exhibits, Financial Statement Schedules and Reports
                       on Form 8-K                                                   7

Signatures......................................................................     8

Index to Exhibits                                                                    9
</TABLE>
<PAGE>   3



                                     PART I

ITEM 1. BUSINESS

THE REGISTRANT

    The Registrant was incorporated in 1982 under the laws of the State of West
Virginia as a one-bank holding company known as Raleigh Bankshares, Inc. On
January 3, 1984, the Bank of Raleigh became a wholly-owned subsidiary of Raleigh
Bankshares.

    Subsequent to 1984, the Board of Directors determined that the name, Raleigh
Bankshares, may have had a constraining effect upon expansion activities. The
shareholders approved an amendment on April 16, 1985, to change Raleigh
Bankshares' name to Horizon Bancorp, Inc. ("Horizon" or "Horizon Bancorp").

    Banking operations are, and are expected to continue to be, Horizon
Bancorp's primary business and major source of revenue. For the most part,
Horizon Bancorp derives its revenues from dividends paid by its subsidiary
banks. The principal role of Horizon Bancorp is to supervise and coordinate the
activities of the subsidiary banks.

    Horizon has five operating subsidiaries, Bank of Raleigh ("Raleigh"),
National Bank of Summers of Hinton ("Summers"), Greenbrier Valley National Bank
("Greenbrier"), The First National Bank in Marlinton ("Marlinton") and The
Twentieth Street Bank ("Twentieth" or "Twentieth Street Bank").

    Summers was acquired by Horizon on June 1, 1985, through a consolidation
between Summers bank and NBS National Bank, a wholly-owned subsidiary of
Horizon.

    Greenbrier and Marlinton were acquired by Horizon on March 31, 1993, through
a merger between Allegheny Bankshares Corporation and Horizon Bancorp, Inc.
Twentieth was acquired by Horizon on August 30, 1996, through a merger between
Twentieth Bancorp, Inc. and Horizon Bancorp, Inc.

    At December 31, 1997, Horizon had consolidated assets of $1,020,281,000
deposits of $841,307,000, and shareholders' equity of $114,022,000.

    Raleigh was originally chartered in 1899 as a state banking corporation with
the name "Bank of Raleigh." It has conducted banking operations in Beckley, West
Virginia, continuously since that time. In 1957, Beckley Industrial Savings and
Loan Company merged into Raleigh, with Raleigh surviving the merger. Crossroads
National Bank, Bradley, West Virginia, merged with and into Raleigh during 1988,
and Crossroads' former office is operated as a branch of Raleigh. During 1997,
Beckley Bancorp, Inc. was merged with and into Raleigh, with one of its two
former branches still in operation as a branch of Raleigh.

    Summers was incorporated in 1895 as a state banking corporation under the
laws of the State of West Virginia with the name "The Bank of Summers." Summers
opened for business in 1895 and operated as a state bank under the laws of the
State of West Virginia from that date until 1906, when the Bank obtained a
national charter and assumed its present name, "National Bank of Summers of
Hinton."

    Greenbrier was incorporated in 1901 as a national banking association with
the name of "First National Bank of Alderson." An Agreement to Consolidate and
Plan of Reorganization dated February 12, 1985, as amended by Amendment dated
October 24, 1985, among Allegheny Bankshares Corporation, Greenbrier Valley Bank
and First National Bank of Alderson ("Agreement; Plan of Reorganization") was
entered into whereby Greenbrier Valley Bank was consolidated with First National
Bank of Alderson and formed a new bank under the charter of First National Bank
of Alderson and the title of Greenbrier Valley National Bank.

    Marlinton was incorporated in 1902 as a national banking association under
the laws of the United States.



                                       1
<PAGE>   4



    Twentieth Street Bank was originally incorporated on September 11, 1905, as
a state bank under the laws of West Virginia, and has operated as such since
that time. In 1983, the Bank became a wholly owned subsidiary of Twentieth
Bancorp, Inc., which was a one-bank holding company. Twentieth Street Bank's
Milton branch was originally a separate corporation (Bank of Milton)
incorporated on September 7, 1904, as a state bank under the laws of West
Virginia and operated as such until being acquired by Twentieth Street Bank on
June 30, 1985. Twentieth Street Bank's West Hamlin branch was originally a
separate corporation (First National Bank of West Hamlin) incorporated on
October 24, 1964, as a national bank. The First National Bank of West Hamlin was
acquired by Twentieth Bancorp, Inc. on December 31, 1984. It continued to
operate as a national bank until January 1, 1990, when its operations became
branches of The Twentieth Street Bank, Inc. In December 1995, Twentieth added a
new full service branch facility in Hamlin, West Virginia on State Route 3
located in Lincoln County.

    During 1995, Horizon, through two of its subsidiary banks, purchased certain
assets and assumed certain liabilities of a regional banking company. Greenbrier
Valley National Bank acquired the regional branch office at Fairlea, Greenbrier
County, on March 31, 1995. Bank of Raleigh acquired regional branch offices
located at Beaver and Sophia, Raleigh County, and at Oak Hill in Fayette County
on May 12, 1995. The assets of these offices acquired by Horizon totaled
approximately $21,000,000.

    The Board of Directors of Horizon implemented a dividend reinvestment plan
in September 1995 for Horizon's shareholders. The purpose of the plan is to
provide Horizon's shareholders with a convenient means of purchasing additional
shares of common stock of Horizon through the investment of dividends. All
shareholders are eligible to participate in the plan. The plan is voluntary, and
all maintenance and transaction costs are paid by Horizon.

FUTURE ACQUISITIONS AND EXPANSIONS

In the fourth quarter of 1997, Horizon announced that it had entered into a
non-binding letter of intent for the acquisition of Bank of Mingo (Mingo)
through a merger of Mingo into Horizon. Mingo operates three banking offices in
West Virginia with total assets of $66.3 million at December 31, 1997. The
transaction is subject to approval by the appropriate regulatory authorities and
the shareholders of Mingo with an expected closing during the second quarter of
1998. The acquisition will be accounted for under the purchase method of
accounting. To date, no definitive merger agreement has been entered into and
no assurance can be given that the transaction will ultimately be consummated.

Horizon regularly evaluates acquisition opportunities and conducts due
diligence activities in connection with possible acquisitions. As a result,
acquisition discussions and in some cases negotiations may take place and
future acquisitions involving cash, debt, or equity securities may occur.
Acquisitions typically involve the payment of a premium over book and market
values and therefore, some dilution of Horizon's book value and net income per
common share may occur in connection with any future acquisitions.

EMPLOYEES

    At the close of 1997, Horizon had 419 full-time equivalent employees.

COMPETITION

    Raleigh's primary market area is generally defined as Raleigh County, West
Virginia. At June 30, 1997, there were eight financial institutions and one
savings bank operating in Raleigh County. Total deposits of the commercial banks
in Raleigh County at June 30, 1997, were approximately $809,035,000 and Raleigh
ranked first with 32.14% of the total deposits. These institutions include One
Valley Bank and United National Bank which are wholly-owned subsidiaries of
state-wide multi-bank holding companies. Raleigh's largest competitor in the
market area reported total deposits of $178,229,000 and the smallest competitor
in the market area had total deposits of $20,199,000.

    Five new banks have been chartered in Raleigh County since 1970. In
addition, one federally-chartered savings and loan association has opened since
1980. Total deposits for Raleigh, however, have increased from the December 31,
1996 level of $256,318,000 to a December 31, 1997 level of $296,829,000.

    The primary market area of Summers is generally defined as Summers County,
West Virginia. At June 30, 1997, there were two banks operating in Summers
County with total deposits of approximately $118,623,000 and National Bank of
Summers holding 51.93% of the market share. Summers had total deposits of
$63,717,000 at December 31, 1997.


                                       2
<PAGE>   5



    The primary market area of Greenbrier is generally defined as Greenbrier
County, West Virginia. Greenbrier's market area is served by five financial
institutions. These institutions include One Valley Bank and First State Bank
and Trust, wholly-owned subsidiaries of state-wide multi-bank holding companies.
At June 30, 1997, total deposits at these five financial institutions were
approximately $442,478,000. Greenbrier is the largest of these five banks with
35.51% of the deposits in Greenbrier County with the other banks within the
market area having total deposits of approximately 64.49% as of that date.
Greenbrier had total deposits of $157,384,000 at December 31, 1997.

    Marlinton's primary market area is generally defined as Pocahontas County,
West Virginia. There are two commercial banks within Marlinton's market area. At
June 30, 1997, total deposits at these two commercial banks were approximately
$101,654,000, with Marlinton holding approximately 50.90% of the total deposits.
Marlinton had total deposits of $58,206,000 at December 31, 1997.

    The primary market area of Twentieth is generally defined as Cabell, Wayne
and Lincoln counties of West Virginia. Seven commercial banks and one federal
savings bank are located in Twentieth's market area with total deposits of
$1,297,000,000 at June 30, 1997. These institutions include One Valley Bank and
Bank One which are all wholly-owned subsidiaries of state-wide multi-bank
holding companies. Twentieth is the second largest of these seven commercial
banks having total deposits of $262,000,000 or 20.18% in their competitive
market. At December 31, 1997, Twentieth had total deposits of $265,171,000.

    Horizon banks are subject to competition from less heavily regulated
entities such as brokerage firms, money market mutual funds, consumer finance
and credit card companies and other financial services companies. For instance,
savings banks, savings and loan associations, credit unions, and issuers of
commercial paper compete for funds and loans. In addition, personal and
corporate trust and investment counseling services are offered by insurance
companies, investment counseling firms and other firms and individuals.

    Until 1992, the various banks and bank holding companies operating in West
Virginia were predominantly owned by shareholders in West Virginia and were
financed by operations arising principally in West Virginia. Since then banking
companies from outside West Virginia including BancOne Corp., Huntington
Bancshares, Incorporated and others have established a substantial presence in
West Virginia.

    In 1994, Congress passed the Riegle-Neal Interstate Banking and Branching
Efficiency Act. Under this Act, bank holding companies are permitted to acquire
banks located in states other than the bank holding company's home state without
regard to whether the transaction is permitted under state law. Commencing on
June 1, 1997, the Act allows national banks and state banks with different home
states to merge across state lines, unless the home state of a participating
bank enacted legislation prior to May 31, 1997, that expressly prohibits
interstate mergers. Additionally, the Act allows banks to branch across state
lines, unless the state where the new branch will be located enacted legislation
restricting or prohibiting de novo interest branching on or before May 31, 1997.
West Virginia adopted legislation, effective May 31, 1997, that allows for
interstate branch banking by merger across state lines and allows for de novo
branching and branching by purchase and assumption on a reciprocal basis with
the home state of the bank in question. The effect of this legislation will
likely be increased competition with West Virginia banks, including the Bank.

SUPERVISION AND REGULATION

    Horizon is a bank holding company within the provisions of the Bank Holding
Company Act of 1956, is registered as such and is subject to supervision by the
Board of Governors of the Federal Reserve System ("Federal Reserve"). Horizon is
also a registered bank holding company within the provisions of the West
Virginia Bank Holding Company laws (W.Va. Code 31A-8A-1 et seq.) ("West Virginia
Act"), and is subject to the supervision of the West Virginia Board of Banking
and Financial Institutions ("Board of Banking") and Commissioner of Banking. The
Bank Holding Company Act and the West Virginia Act require Horizon to secure the
prior approval of the Federal Reserve and the Board of Banking before Horizon
acquires ownership or control of more than 5% of the voting shares or
substantially all of the assets of any institution, including another bank. In
addition, the West Virginia Act prohibits a depository



                                       3
<PAGE>   6


institution, including a bank holding company, from controlling more than 20% of
the total deposits of all depository institutions in West Virginia.

    As a bank holding company, Horizon is required to file with the Federal
Reserve and the Commissioner of Banking annual reports and such additional
information as the Federal Reserve may require pursuant to the Bank Holding
Company Act and the Banking Commissioner may require under the West Virginia
Act. The Federal Reserve and the Banking Commissioner may also make examinations
of Horizon and any or all of its subsidiaries. Further, under Section 106 of the
1970 Amendments to the Bank Holding Act and the regulations of the Federal
Reserve, a bank holding company and its subsidiaries are prohibited from
engaging in certain tie-in arrangements in connection with any extension of
credit or any provision of credit, sale or lease of property or furnishing of
services. In addition, pursuant to the United States Code, Horizon is considered
an "affiliate" of the Banks and, as such, the Banks are subject to statutory
limitations in extending credit to, or investing funds in, Horizon, and in
accepting Horizon's securities or other obligations as collateral for any
advances made by the Banks to any other entity or person.

    Horizon is required to register annually with the Commissioner of Banking of
West Virginia ("Commissioner") and to pay a registration fee to the Commissioner
based on the total deposits in the banks with respect to which Horizon is a bank
holding company. The registration fee is limited to ten dollars per million
dollars in deposits rounded off to the nearest million dollars. Horizon is also
under the regulatory control of the Commissioner.

    The operations of Raleigh and Twentieth are subject to federal and state
statutes, which apply to state-chartered banks and to non-members of the Federal
Reserve. Raleigh and Twentieth's operations are also subject to regulations of
the Board of Banking, the Federal Reserve and the Federal Deposit Insurance
Corporation ("FDIC").

    The primary supervisory authorities of Raleigh and Twentieth are the FDIC
and the Commissioner of Banking. The FDIC and Banking Commissioner regularly
examine such areas as reserves, loans, investments, management practices and
other aspects of Raleigh and Twentieth's operations. Independent of those
examinations, both supervisory authorities also conduct regular examinations of
Raleigh and Twentieth's Trust Department. These examinations are designed for
the protection of Raleigh and Twentieth's depositors and not for its
shareholders. In addition to these regular examinations, Raleigh and Twentieth
must furnish to the FDIC and the Board of Banking quarterly reports containing
full and accurate statements of their affairs.

    The operations of Greenbrier, Marlinton and Summers are subject to federal
and state statutes which apply to national banks and to members of the Federal
Reserve. Greenbrier's, Marlinton's and Summers' operations are also subject to
regulations of the FDIC, the Federal Reserve, and the Office of the Comptroller
of the Currency ("Comptroller"). The primary supervisory authority of
Greenbrier, Marlinton and Summers is the Comptroller, which regularly examines
such areas as reserves, loans, investments, management practices, and other
aspects of its affairs.

    The Banks are members of the FDIC, and their deposits are insured as
provided by law. Raleigh and Twentieth are members of the Federal Reserve System
and also carry FDIC insurance.

    In addition to the effect of general economic conditions, the earnings of
Horizon are affected by the fiscal and monetary policies of the Federal Reserve,
which regulates the national money supply in order to mitigate recessionary and
inflationary pressures. The techniques used by the Federal Reserve include
setting the reserve requirements of member and nonmember banks, establishing
interest rates on time and savings deposits and the discount rate on member bank
borrowings, and conducting open market operations in United States government
securities to exercise control over the supply of money and credit.

    The policies of the Federal Reserve have a direct and indirect effect on the
amount of bank loans and deposits, and the interest rates charged and paid
thereon. While the impact of current economic conditions and the policies of the
Federal Reserve and other regulatory authorities designed to deal with these




                                       4
<PAGE>   7


conditions upon the future business and earnings of the Banks cannot be
accurately predicted, those policies can materially affect the revenues and
income of commercial banks.

COMPLIANCE WITH ENVIRONMENTAL LAWS

    The costs and effects of compliance with federal, state and local
environmental laws are not expected to have a material effect on Horizon or the
Banks. In the future, the Banks may incur costs for environmental control
facilities related to properties obtained through foreclosure proceedings,
however, the amount of such costs, if any, is not determinable at this time.

STATISTICAL DISCLOSURE BY BANK HOLDING COMPANIES

    Statistical disclosures required by bank holding companies are included in
"Five-Year Selected Financial Summary" on page 15 and in "Management's
Discussion and Analysis of Operations" set forth on pages 15 through 30 of
Horizon's Annual Report to Shareholders for the fiscal year ended December 31,
1997. That information is incorporated herein by reference.

ITEM 2. PROPERTIES

    Horizon's principal office is located in the Bank of Raleigh at One Park
Avenue, Beckley, West Virginia. Raleigh has a full-service branch consisting of
the former offices of Crossroads National Bank at the Crossroads Mall, Bradley,
West Virginia. In addition, a full-service branch is located at the corner of
Main and Kanawha Streets, Beckley, West Virginia. During 1995, branches in
Kroger supermarkets were acquired from a regional bank and are located at Beaver
and Sophia, Raleigh County, and at Oak Hill in Fayette County. During 1997,
branches were acquired through the purchase of Beckley Bancorp and are located
at Harper Road, which is a full service location, and Main Street. The Main
Street location is not being utilized at this time and has been listed for sale.

    The operations of Summers are conducted at its main office of 123 Temple
Street in Hinton, West Virginia and a full-service branch facility at Country
Roads Plaza on Stokes Drive.

     Greenbrier's main office is located at 109 South Jefferson Street,
Lewisburg, West Virginia. Greenbrier has five full service branch offices
located in Alderson, Rainelle, North Lewisberg, Fairlea, and Rupert, West
Virginia. During 1995, a branch in a Kroger supermarket was acquired from a
regional bank and is located at Fairlea.

    The principal office of Marlinton is located at 300 Eighth Street,
Marlinton, Pocahontas County, West Virginia.

    The operations of Twentieth are conducted at 1900 Third Avenue, Huntington,
West Virginia. Twentieth has four full service branch offices located at Route
60 East, Huntington, Milton, Hamlin, and West Hamlin, West Virginia. In
addition, a limited-service facility is located on Fifth Avenue, Huntington,
West Virginia.

    Horizon also offers services to its customers at various locations within
the service area through automated teller machines. The automated teller
machines permit customers to make deposits, withdrawals, and loan payments at
these locations, and the banks have joined a regional network.

ITEM 3. LEGAL PROCEEDINGS

    Horizon and its banks are involved in various legal proceedings arising in
the normal course of business. It is anticipated that the ultimate resolution of
these proceedings will not have a material adverse effect on the financial
position or operations of Horizon or the banks.

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

    None.




                                       5
<PAGE>   8


                                     PART II

ITEM 5. MARKET FOR THE REGISTRANT'S COMMON STOCK AND RELATED SHAREHOLDER MATTERS

    The section of Management's Discussion and Analysis of Financial Condition
and Results of Operations entitled "Market and Dividend Information" on page 30
of Horizon's 1997 Annual Report to Shareholders is incorporated herein by
reference.

ITEM 6. SELECTED FINANCIAL DATA

    Table 1, "Five-Year Selected Financial Summary," on page 15 of Horizon's
1997 Annual Report to Shareholders is incorporated herein by reference.

ITEM 7. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
        OF OPERATIONS

    Management's Discussion and Analysis of Financial Condition and Results of
Operations on pages 15 through 30 of Horizon's 1997 Annual Report to
Shareholders is incorporated herein by reference.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

    The report of independent auditors and consolidated financial statements
included on pages 31 through 50 of Horizon's 1997 Annual Report to Shareholders
are incorporated herein by reference.

ITEM 9. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND
        FINANCIAL DISCLOSURE

    None.

                                    PART III

ITEM 10. DIRECTORS AND EXECUTIVE OFFICERS OF HORIZON

    The information set forth in the sections "Management Nominees to the Board
of Directors," "Executive Officers of Horizon" and "Section 16(a) Beneficial
Ownership Reporting Compliance" on pages 3 through 9, pages 10 through 11 and
pages 11 through 13, respectively, of Horizon's definitive Proxy Statement for
the 1997 Annual Meeting of Shareholders are incorporated herein by reference.

ITEM 11. EXECUTIVE COMPENSATION

The information set forth in the sections "Executive Compensation" on pages 14
through 18 and "Compensation of Directors" on page 9 of Horizon's definitive
Proxy Statement for the 1997 Annual Meeting of Shareholders are incorporated
herein by reference.

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

The information set forth in the section "Security Ownership of Certain
Beneficial Owners and Management" on pages 11 through 13 of Horizon's definitive
Proxy Statement for the 1998 Annual Meeting of Shareholders are incorporated
herein by reference.


ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

    The information set forth in the section "Certain Relationships and Related
Transactions and Compensation and Benefits Committee Interlocks and Insider
Participation" on pages 22 through 23 of Horizon's definitive Proxy Statement
for the 1997 Annual Meeting of Shareholders and the information set forth in
Note 4 on page 41 of Horizon's Annual Report to Shareholders are incorporated
herein by reference.

                                       6

<PAGE>   9


                                     PART IV

ITEM 14. EXHIBITS, FINANCIAL STATEMENT SCHEDULES AND REPORTS ON FORM 8-K

     (a)(1) Financial Statements on pages 15 through 50 of Horizon's 1997 Annual
     Report to Shareholders are incorporated by reference in Part II, Item 8,
     of this report:

     Consolidated balance sheets--December 31, 1997 and 1996

     Consolidated statements of income--years ended December 31, 1997, 1996, and
     1995

     Consolidated statements of shareholders' equity--years ended December 31,
     1997, 1996, and 1995

     Consolidated statements of cash flows--years ended December 31, 1997, 1996,
     and 1995

     Notes to consolidated financial statements--December 31, 1997

     (a)(2) All schedules are omitted, as the required information is
     inapplicable and the information is presented in the Consolidated Financial
     Statements and related Notes thereto.

     (a)(3) Exhibits required by item 601 - see listing of exhibits on page 9

     (b) None.

     (c) Exhibits - exhibits for this 10-K begin on page 10




                                       7
<PAGE>   10


                                   SIGNATURES

    Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the registrant has duly caused this report to be signed on
its behalf by the undersigned, thereunto duly authorized on the 27th day of
March, 1998.

HORIZON BANCORP, INC.

By: /s/ FRANK S. HARKINS, JR.
-------------------------------------------------
Chairman of the Board and Chief Executive Officer

    Pursuant to the requirements of the Securities Exchange Act of 1934, this
report has been signed by the following persons on behalf of the registrant and
in the capacities indicated on the 27th day of March, 1998.

<TABLE>
<CAPTION>
        NAME                                             TITLE
        ----                                             -----
<S>                                       <C>
/s/ FRANK S. HARKINS, JR.                  Chairman of the Board and Chief Executive Officer
--------------------------------           (Principal Executive Officer)

/s/ PHILIP L. MCLAUGHLIN                   President and Chief Operating Officer
--------------------------------

/s/ C. DUANE BLANKENSHIP                   Vice President and Chief Financial Officer
--------------------------------           (Principal Accounting Officer)

/s/ DAVID W. HAMBRICK                      Executive Vice President
--------------------------------

/s/ E. M. PAYNE III                        Secretary
--------------------------------

/s/ JOHN M. ALDERSON IV                    Director
--------------------------------

/s/ JOSEPH M. BLANKENSHIP                  Director
--------------------------------

/s/ W. H. FILE III                         Director
--------------------------------

/s/ ALBERT M. TIECHE, JR.                  Director
--------------------------------

/s/ B.C. MCGINNIS, III                     Executive Vice President
--------------------------------

/s/ WILLIAM C. DOLIN                       Director
--------------------------------

/s/ R. T. ROGERS                           Director
--------------------------------

/s/ TRACY W. HYLTON II                     Director
--------------------------------

/s/ JACK G. BAZEMORE                       Director
--------------------------------

/s/ ROBERT L. KOSNOSKI                     Director
--------------------------------

/s/ THOMAS E. LILLY                        Director
--------------------------------

/s/ CLARENCE E. MARTIN                     Director
--------------------------------

/s/ CAROLYN H. MCCULLOCH                   Director
--------------------------------

/s/ JACK MCGINNIS                          Director
--------------------------------

/s/ THOMAS L. MCGINNIS                     Director
--------------------------------

/s/ HARPER W. NELSON                       Director
--------------------------------

/s/ RODNEY H. PACK                         Director
--------------------------------

/s/ SHARON H. ROWE                         Director
--------------------------------

/s/ PHILLIP W. CAIN                        Director
--------------------------------

/s/ JAMES E. SONGER                        Director
--------------------------------
</TABLE>



                                       8
<PAGE>   11



ITEM 14 - Index to Exhibits


<TABLE>
<CAPTION>
Exhibit                                                      Page Reference


<S>                                                                 <C>
(3) (i)      Articles of Incorporation                              10
    (ii)     By-Laws                                                10

(12)         Statements re: Computation of Ratios                   11

(13)         Horizon Bancorp, Inc. 1997 Annual Report               12

(21)         Subsidiaries of Registrant                             54

(23.1)       Consent of Ernst & Young LLP                           55

(23.2)       Consent of Diamond, Leftwich, Goheen & Dunn            56

(27)         Financial Data Schedule                                57

(99)         Report of Diamond, Leftwich, Goheen & Dunn             58
</TABLE>




                                       9