As Filed with the Securities and Exchange Commission on December 20, 2002
                                                   Registration No. 333-

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

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                        FORM S-8 REGISTRATION STATEMENT
                        UNDER THE SECURITIES ACT OF 1933

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

               MISSOURI                                        43-1262037
    (State or other jurisdiction of                         (I.R.S. Employer
     incorporation or organization)                      Identification Number)

           2122 KRATKY ROAD
          ST. LOUIS, MISSOURI                                    63114
(Address of principal executive offices)                       (Zip Code)

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                            ALLEGIANT BANCORP, INC.
                           2002 STOCK INCENTIVE PLAN
                            (Full title of the plan)

                                   ----------

                                 SHAUN R. HAYES
                                2122 KRATKY ROAD
                              ST. LOUIS, MISSOURI
                                     63114
                    (Name and address of agent for service)

                           TELEPHONE: (314) 692-8200

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                                    Copy to:

                              THOMAS A. LITZ, ESQ.
                              THOMPSON COBURN LLP
                               ONE US BANK PLAZA
                           ST. LOUIS, MISSOURI 63101
                                 (314) 552-6000



                                               CALCULATION OF REGISTRATION FEE

=============================================================================================================================
                                                            PROPOSED MAXIMUM          PROPOSED MAXIMUM           AMOUNT OF
  TITLE OF SECURITIES TO BE           AMOUNT TO BE         OFFERING PRICE PER        AGGREGATE OFFERING        REGISTRATION
          REGISTERED                   REGISTERED               SHARE(1)                  PRICE(1)                  FEE
-----------------------------------------------------------------------------------------------------------------------------
                                                                                                    
Common Stock, $.01 par value        800,000 shares              $17.46                $13,968,000.00            $1,285.06
=============================================================================================================================


(1) Estimated solely for purposes of computing the Registration Fee pursuant
    to the provisions of Rule 457(h), based upon the average of the high and
    low sale prices of common stock, of the Company as reported on the
    Nasdaq National Market on December 16, 2002.






         The undersigned Registrant hereby files this Registration Statement
on Form S-8 (the "Registration Statement") to register 800,000 shares of
Allegiant Bancorp, Inc. ("Allegiant" or the "Company") common stock, $0.01
par value, for issuance to optionees under the Allegiant Bancorp, Inc. 2002
Stock Incentive Plan (the "Plan").

Item 3.  Incorporation of Documents by Reference.
         ---------------------------------------

         The following documents filed by the Company with the Securities
and Exchange Commission under the Securities Exchange Act of 1934, as
amended (the "Exchange Act") are incorporated herein by reference:

             1.   Allegiant's Annual Report on Form 10-K for the year ended
                  December 31, 2001;

             2.   Allegiant's Quarterly Reports on Form 10-Q/A for the
                  quarters ended March 31, 2002 and June 30, 2002, and Form
                  10-Q for the quarter ended September 30, 2002; and

             3.   The description of Allegiant's Common Stock contained in
                  its Registration Statement on Form S-1, Registration No.
                  33-22739, dated June 27, 1988, including any amendments or
                  reports filed for the purpose of updating such
                  description. In connection with the merger of Allegiant
                  with Southside Bancshares Corp. ("SBCO") on September 28,
                  2001, Allegiant merged with and into Southside. However,
                  Allegiant was, in all practical respects, the entity
                  surviving the Merger and immediately after the Merger,
                  Southside changed its name to "Allegiant Bancorp, Inc."
                  Since SBCO was technically the surviving entity, the
                  description of Common Stock incorporated herein by
                  reference is the description of Common Stock of SBCO.

         Such incorporation by reference shall not be deemed to incorporate
by reference the information referred to in Item 402(a)(8) of Regulation
S-K.

         All documents filed by the Company pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Exchange Act after the date hereof and prior to
the filing of a post-effective amendment which indicates that all securities
offered hereby have been sold or which deregisters all securities remaining
unsold, shall be deemed to be incorporated by reference herein and made a
part hereof from the date any such document is filed. The information
relating to the Company contained in this Registration Statement does not
purport to be complete and should be read together with the information in
the documents incorporated by reference herein. Any statement contained
herein or in a document incorporated herein by reference shall be deemed to
be modified or superseded for purposes hereof to the extent that a
subsequent statement contained herein or in any other subsequently filed
document incorporated by reference herein modifies or supersedes such
statement. Any such statement so modified or superseded shall not be deemed,
except as so modified or superseded, to constitute a part hereof.

         Where any document or part thereof is incorporated by reference in
the Registration Statement, the Company will provide without charge to each
person to whom a Prospectus with respect to the Plan is delivered, upon
written or oral request of such person, a copy of any and all of the
information incorporated by reference in the Registration Statement,
excluding exhibits unless such exhibits are specifically incorporated by
reference.





Item 6.  Indemnification of Directors and Officers.
         -----------------------------------------

         Section 351.355(1) and Section 351.355(2) of The General and
Business Corporation Law of Missouri ("MGBCL") provide that a corporation
may indemnify any person who was or is a party or is threatened to be made a
party to any threatened, pending or completed action, suit or proceeding by
reason of the fact that he is or was a director, officer, employee or agent
of the corporation, or is or was serving at the request of the corporation
as a director, officer, employee or agent of another corporation,
partnership, joint venture, trust or other enterprise, against expenses,
including attorneys' fees, judgments, fines and amounts paid in settlement
actually and reasonably incurred by him in connection with such action, suit
or proceeding if he acted in good faith and in a manner he reasonably
believed to be in or not opposed to the best interests of the corporation,
and, with respect to any criminal action or proceeding, had no reasonable
cause to believe his conduct was unlawful, except that, in the case of an
action or suit by or in the right of the corporation, the corporation may
not indemnify such persons against judgments and fines, and no person shall
be indemnified as to any claim, issue or matter as to which such person
shall have been adjudged to be liable for negligence or misconduct in the
performance of his duty to the corporation, unless and only to the extent
that the court in which the action or suit was brought determines upon
application that such person is fairly and reasonably entitled to indemnity
for proper expenses. Section 351.355(3) of the MGBCL, provides that, except
as otherwise provided in the Company's articles of incorporation or bylaws,
to the extent that a director, officer, employee or agent of the corporation
has been successful on the merits or otherwise in the defense of any such
action, suit or proceeding or any claim, issue or matter therein, he shall
be indemnified against expenses, including attorney's fees, actually and
reasonably incurred in connection with such action, suit or proceeding.
Section 351.355(7) of the MGBCL, provides that a Missouri corporation may
provide additional indemnification to any person indemnifiable under Section
351.355(1) or Section 351.355(2), provided such additional indemnification
is authorized by the corporation's articles of incorporation or an amendment
thereto or by a shareholder-approved bylaw or agreement, and provided
further that no person shall thereby be indemnified against conduct which
was finally adjudged to have been knowingly fraudulent, deliberately
dishonest or willful misconduct.

         Article Eleven of the Company's Amended and Restated Articles of
Incorporation provides that the personal liability of a director to the
Company or its shareholders for breach of their fiduciary duty is eliminated
except as otherwise set forth therein. Article XII of the Company's Amended
and Restated Bylaws contains a provision that provides indemnification of
the directors and officers of the Company except as otherwise provided
therein. Article XII also provides indemnification of the employees and
agents of the Company to the extent the board of directors deems appropriate
except as otherwise provided therein.

         Pursuant to a policy of directors' and officers' liability
insurance, the Company's officers and directors are insured, subject to the
limits, retention, exceptions and other terms and conditions of such policy,
against liability for any actual or alleged error, misstatement, misleading
statement, act or omission, or neglect or breach of duty by the directors or
officers of the Company in the discharge of their duties solely in their
capacity as directors or officers of the Company, individually or
collectively, or any matter claimed against them solely by reason of their
being directors or officers of the Company.

Item 8.  Exhibits.
         --------

         See Exhibit Index located at page 7 hereof.


                                    -2-




Item 9.  Undertakings.
         ------------

         (a)      The Company hereby undertakes:

                  (1)      To file, during any period in which offers and
         sales are being made, a post-effective amendment to this
         Registration Statement:

                           (i)      To include any prospectus required by
                  Section 10(a)(3) of the Securities Act of 1933;

                           (ii)     To reflect in the prospectus any facts
                  or events arising after the effective date of the
                  Registration Statement (or the most recent post-effective
                  amendment thereof), which, individually or in the
                  aggregate, represent a fundamental change in the
                  information set forth in the Registration Statement; and

                           (iii)    To include any material information with
                  respect to the plan of distribution previously disclosed
                  in the Registration Statement or any material change to
                  such information in the Registration Statement;

provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if
the Registration Statement is on Form S-3 or Form S-8, and the information
required to be included in a post-effective amendment by those paragraphs is
contained in periodic reports filed by the Company pursuant to Section 13 or
Section 15(d) of the Exchange Act that are incorporated by reference in the
Registration Statement.

                  (2)      That, for the purpose of determining any
         liability under the Securities Act of 1933 (the "Act"), each such
         post-effective amendment shall be deemed to be a new registration
         statement relating to the securities offered therein, and the
         offering of such securities at that time shall be deemed to be the
         initial bona fide offering thereof.

                  (3)      To remove from registration by means of a
         post-effective amendment any of the securities being registered
         which remain unsold at the termination of the offering.


         (b)      The Company hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of
the Company's annual report pursuant to Section 13(a) or Section 15(d) of
the Exchange Act (and, where applicable, each filing of an employee benefit
plan's annual report pursuant to Section 15(d) of the Exchange Act) that is
incorporated by reference in the Registration Statement shall be deemed to
be a new registration statement relating to the securities offered therein,
and the offering of such securities at that time shall be deemed to be the
initial bona fide offering thereof.

         (c)      Insofar as indemnification for liabilities arising under
the Act may be permitted to directors, officers and controlling persons of
the Company pursuant to the foregoing provisions, or otherwise, the Company
has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the
Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
Company of expenses incurred or paid by a director, officer or controlling
person of the Company in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Company will, unless in
the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question


                                     -3-




whether such indemnification by it is against public policy as expressed in
the Act and will be governed by the final adjudication of such issue.


                                    * * *



                                     -4-




                                 SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, the
Company certifies that it has reasonable grounds to believe that it meets
all of the requirements for filing this Registration Statement on Form S-8
and has duly caused this Registration Statement to be signed on its behalf
by the undersigned, thereunto duly authorized, in the County of St. Louis,
State of Missouri, on December 19, 2002.

                                   ALLEGIANT BANCORP, INC.


                                   By:/s/ Shaun R. Hayes
                                      --------------------------------------
                                       Shaun R. Hayes
                                       President and Chief Executive Officer



                              POWER OF ATTORNEY

         Each person whose signature appears below hereby constitutes and
appoints Shaun R. Hayes and Thomas A. Daiber, and each of them, the
undersigned's true and lawful attorneys-in-fact and agents, with full power
of substitution and resubstitution, for the undersigned and in the
undersigned's name, place and stead, in any and all capacities, to sign any
and all amendments (including post-effective amendments) to this
Registration Statement on Form S-8 with respect to the Allegiant Bancorp,
Inc. 2002 Stock Incentive Plan, and to file the same, with exhibits and any
and all other documents filed with respect thereto, with the Securities and
Exchange Commission (or any other governmental or regulatory authority),
granting unto said attorneys-in-fact and agents full power and authority to
do and to perform each and every act and thing requisite and necessary to be
done in ratifying and confirming all that said attorneys-in-fact and agents
or their substitute or substitutes, may lawfully do or cause to be done by
virtue hereof.

         Pursuant to the requirements of the Securities Act of 1933, as
amended, this Registration Statement has been signed by the following
persons in the capacities and on the date indicated.



Name                                 Title                                     Date
----                                 -----                                     ----

                                                                         
/s/ Shaun R. Hayes                   President, Chief Executive Officer,       December 19, 2002
------------------------------       and Director (principal executive
Shaun R. Hayes                       officer)

/s/ Thomas A. Daiber                 Executive Vice President and Chief        December 19, 2002
------------------------------       Financial Officer (principal financial
Thomas A. Daiber                     and accounting officer)

/s/ Robert L. Chambers               Director                                  December 19, 2002
------------------------------
Robert L. Chambers




                                     -5-





Name                                 Title                                     Date
----                                 -----                                     ----

                                                                         


/s/ Leland B. Curtis                 Director                                  December 19, 2002
------------------------------
Leland B. Curtis


/s/ Kevin R. Farrell                 Director                                  December 19, 2002
------------------------------
Kevin R. Farrell


/s/ Richard C. Fellhauer             Director                                  December 19, 2002
------------------------------
Richard C. Fellhauer


/s/ Leon A. Felman                   Director                                  December 19, 2002
------------------------------
Leon A. Felman


/s/ Douglas P. Helein                Director                                  December 19, 2002
------------------------------
Douglas P. Helein


/s/ Michael R. Hogan                 Director                                  December 19, 2002
------------------------------
Michael R. Hogan


/s/ C. Virginia Kirkpatrick          Director                                  December 19, 2002
------------------------------
C. Virginia Kirkpatrick


/s/ Nancy C. Pechloff                Director                                  December 19, 2002
------------------------------
Nancy C. Pechloff


/s/ Thomas M. Teschner               Director                                  December 19, 2002
------------------------------
Thomas M. Teschner


/s/ Robert E. Wallace, Jr.           Director                                  December 19, 2002
------------------------------
Robert E. Wallace, Jr.


/s/ John L. Weiss                    Director                                  December 19, 2002
------------------------------
John L. Weiss


/s/ Marvin S. Wool                   Director                                  December 19, 2002
------------------------------
Marvin S. Wool


/s/ Lee S. Wielansky                 Director                                  December 19, 2002
------------------------------
Lee S. Wielansky




                                    -6-




                                EXHIBIT INDEX
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Reg. S-K
Item 601
Exhibit No.                        Exhibit
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   4.1       Amended and Restated Articles of Incorporation of the Company,
             filed as Annex E to the Company's Registration Statement on
             Form S-4 (Reg. No. 333-63212), incorporated herein by reference

   4.2       Amended and Restated Bylaws of the Company, filed as Annex F to
             the Company's Registration Statement on Form S-4 (Reg. No.
             333-63212), incorporated herein by reference

   4.3       Allegiant Bancorp, Inc. 2002 Stock Incentive Plan, filed as
             Annex A to the Company's Proxy Statement for the Company's 2002
             Annual Meeting, is incorporated herein by reference

   5.1       Opinion of Thompson Coburn LLP regarding the legality of the
             shares being registered filed herewith

   23.1      Consent of Thompson Coburn LLP (included in Exhibit 5.1)

   23.2      Consent of Ernst & Young LLP filed herewith

   24        Power of Attorney (set forth on the signature page hereto)


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