As filed with the Securities and Exchange Commission on May 19, 2000.

                                                  Registration No. 333-_________

================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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

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

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

                              BANKFIRST CORPORATION
             (Exact name of registrant as specified in its charter)

           TENNESSEE                                     58-1790903
(State or other jurisdiction of             (I.R.S. Employer Identification No.)
incorporation or organization)

                                625 Market Street
                           Knoxville, Tennessee 37902
                    (Address of principal executive offices)

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

                              BANKFIRST CORPORATION
                                STOCK OPTION PLAN

                            (Full title of the plan)

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

                                 Fred R. Lawson
                      President and Chief Executive Officer
                              BankFirst Corporation
                                625 Market Street
                           Knoxville, Tennessee 37902
                                 (865) 595-1100

            (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)

                                 With a copy to:

                            Jack H. McCall, Jr., Esq.
                                Hunton & Williams
                              2000 Riverview Tower
                              900 South Gay Street
                           Knoxville, Tennessee 37902
                                 (865) 549-7700

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

                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
===================================================================================================================
                                                        Proposed maximum      Proposed maximum
      Title of securities            Amount to be        offering price          aggregate            Amount of
       to be registered               registered            per share          offering price     registration fee
-------------------------------------------------------------------------------------------------------------------
<S>                                <C>                       <C>                <C>                    <C>
Common Stock, par value $2.50      3,125,000 shares          $8.16*             $25,500,000*           $6,732*
per share
===================================================================================================================
</TABLE>

(*) Pursuant to Rule 457(c) and (h)(1) of the Securities Act of 1933, as amended
(the "Securities Act"), and solely for the purposes of calculating the
registration fee, the registration fee was calculated on the basis of the
average of the high and low sales prices for shares of BankFirst Corporation's
Common Stock on the Nasdaq Stock Market on May 15, 2000, as reported in The Wall
Street Journal.

================================================================================

<PAGE>

                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

Item 1. Plan Information.

      Not required to be filed with the Securities and Exchange Commission (the
"Commission").

Item 2. Registrant Information and Employee Plan Annual Information.

      Not required to be filed with the Commission.


                                      I-1
<PAGE>

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference.

      The following documents filed by BankFirst Corporation (the "Company")
with the Securities and Exchange Commission (the "Commission") under the
Securities and Exchange Act of 1934 (the "Exchange Act"), are hereby
incorporated by reference into this Registration Statement:

      (a)   the Company's Annual Report on Form 10-K for the fiscal year ended
            December 31, 1999;

      (b)   the Company's Current Report on Form 8-K, dated March 21, 2000;

      (c)   the Company's Current report on Form 8-K, dated April 17, 2000; and

      (d)   the Company's Quarterly Report on Form 10-Q for the quarterly period
            ended March 31, 2000.

      Additionally incorporated by reference into this Registration Statement is
the Description of BankFirst Capital Stock section of the Company's Registration
Statement on Form S-1, as amended (Registration No. 333-57147).

      In addition to the foregoing, all documents subsequently filed by the
Company pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act,
prior to the filing of a post-effective amendment which indicates that all
securities registered hereunder have been issued or which deregisters all
securities offered then remaining unsold, shall be deemed incorporated by
reference in this Registration Statement and to be a part hereof from the date
of the filing of such documents. Any statement, including financial statements,
contained in a document incorporated or deemed to be incorporated by reference
herein shall be deemed to be modified or superseded for purposes of this
Registration Statement to the extent that a statement contained herein or in any
other subsequently filed document which also is or is deemed to be 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 of this Registration Statement.

      The Company will promptly provide without charge to each person to whom a
prospectus is delivered a copy of any or all information that has been
incorporated herein by reference (not including exhibits to the information that
is incorporated by reference unless such exhibits are specifically incorporated
by reference into such information) upon the written or oral request of such
person directed to BankFirst Corporation, 625 Market Street, Knoxville,
Tennessee 37902, (865) 595-1100.

Item 4. Description of Securities.

      Not applicable.

Item 5. Interests of Named Experts and Counsel.

      Not applicable.

Item 6. Indemnification of Directors and Officers.

      The Charter and Bylaws of the Company provide for the indemnification of
the Company's directors, officers, employees and agents to the full extent
permitted by the Tennessee Business Corporation Act (the "TBCA").


                                      II-1
<PAGE>

      The Company's directors, officers, employees and agents who successfully
defend any threatened, pending or completed action, suit or proceeding to which
they were made a party by reason of their status as a director, officer,
employee or agent of the Company are entitled to indemnification against all
expenses actually and reasonably incurred by them in connection with such
action, suit or proceeding.

      Indemnification may be provided by the Company in other situations upon
court order or upon a determination by (1) a disinterested majority of the Board
of Directors of the Company; (2) independent legal counsel in a written opinion;
or (3) a majority of the shareholders of the Company that indemnification of the
director, officer, employee or agent is proper because such person met the
applicable standard of conduct specified by the TBCA and the Company's Charter
and Bylaws. Indemnification may be authorized if the individual (1) acted in
good faith; (2) reasonably believed that his conduct was in or not opposed to
the best interest of the corporation; and (3) in the case of any criminal
proceeding, had no reasonable cause to believe his conduct was unlawful. The
termination of any action, suit or proceeding by judgment, order, settlement,
conviction, or plea of nolo contendere or its equivalent shall not, of itself,
create a presumption that the above standard of conduct has not been met.

      No director of the Company can be held personally liable to the
corporation for monetary damages for any breach of his fiduciary duty to the
corporation; provided that a director may be liable (1) for breach of the
director's duty of loyalty to the corporation and its shareholders; (2) for acts
or omissions not in good faith or involving intentional misconduct or a knowing
violation of law; (3) for any action in which the director did not meet the
applicable standard of conduct; and (4) for any transaction from which the
director derived an improper personal benefit.

      The TBCA provides that the Company may not indemnify a director in
connection with any action, suit or proceeding in which a judgment or other
final adjudication established the director's liability (1) to the corporation;
(2) for receipt of an improper personal benefit; (3) for breach of the
director's duty of loyalty to the corporation or its shareholders; (4) for acts
or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law; or (5) for unlawful distributions pursuant to TBCA ss.
48-18-304.

      To the extent that the foregoing indemnification provisions purport to
include indemnification for liabilities arising under the Securities Act of
1933, as amended (the "Securities Act"), in the opinion of the Commission such
indemnification is contrary to public policy and is, therefore, unenforceable.

      In addition, the TBCA and the Company's Charter and Bylaws authorize the
Company to purchase officer and director liability insurance. The Company has
officer and director liability insurance in the amount of $5 million.

Item 7. Exemption from Registration Claimed.

      Not applicable.

Item 8. Exhibits.

      The following exhibits are filed as part of this Registration Statement:

Exhibit No.
-----------
4.1         Amended and Restated Charter of BankFirst Corporation (previously
            filed as Exhibit 3.1 to the Company's Registration Statement on Form
            S-4 (Registration No. 333-52051) and incorporated herein by
            reference)

4.2         Bylaws of BankFirst Corporation (previously filed as Exhibit 3.2 to
            the Company's Registration Statement on Form S-4 (Registration No.
            333-52051) and incorporated herein by reference)

4.3         BankFirst Corporation Stock Option Plan, as amended


                                      II-2
<PAGE>

Exhibit No.
-----------
5.1         Opinion of Ritchie & Johnson, PLC as to the legality of the shares
            of common stock of the Company being registered

15.1        Awareness Letter of Crowe, Chizek and Company LLP

23.1        Consent of Ritchie & Johnson, PLC (included in Exhibit 5.1 to the
            Registration Statement)

23.2        Consent of Crowe, Chizek and Company LLP

23.3        Consent of G.R. Rush & Company, P.C.

24.1        Power of Attorney (included on signature page)

Item 9. Undertakings.

      (a) The undersigned registrant hereby undertakes:

            1. To file, during any period in which offers or 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;

                  (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 not previously disclosed in the
                        registration statement or any material change in 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 with or furnished to the Commission by the registrant
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, 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 undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act, each filing of the
registrant's annual report pursuant to Section 13(a) or 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
Securities Act may be permitted to directors, officers and controlling persons
of the registrant pursuant to the foregoing provisions, or otherwise, the


                                      II-3
<PAGE>

registrant has been advised that in the opinion of the Commission such
indemnification is against public policy as expressed in the Securities Act, and
is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the registrant of expenses
incurred or paid by a director, officer or controlling person of the registrant
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 registrant 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 whether such indemnification by it is against public
policy as expressed in the Securities Act and will be governed by the final
adjudication of such issue.


                                      II-4
<PAGE>

                                   SIGNATURES

      Pursuant to the requirements of the Securities Act, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing 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 City of Knoxville, State of Tennessee, on the 19th day of
May, 2000.

                                     BANKFIRST CORPORATION

                                     By: /s/  Fred R. Lawson
                                         -------------------------------------
                                         Fred R. Lawson
                                         President and Chief Executive Officer


                                POWER OF ATTORNEY

      Each of the undersigned, in his capacity as officer or director, or both,
as the case may be, of BankFirst Corporation does hereby appoint Fred R. Lawson
and C. David Allen, and each of them severally, his true and lawful attorneys or
attorney to execute in his name, place and stead, in his capacity as director or
officer, or both as the case may be, this Registration Statement and any and all
amendments and post-effective amendments thereto, and all instruments necessary
or incidental in connection therewith and to file the same with the Securities
and Exchange Commission. Each of said attorneys shall have power to act
hereunder with or without the other attorney and shall have full power and
authority to do and perform in the name and on behalf of each of said directors
or officers, or both as the case may be, every act whatsoever requisite or
necessary to be done in the premises, as fully and to all intents and purposes
as which each of said officers or directors, or both as the case may be, might
or could do in person, hereby ratifying and confirming all that said attorneys
or attorney may lawfully do or cause to be done by virtue hereof.

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

         Signature                    Title                          Date
         ---------                    -----                          ----

/s/  James L. Clayton          Chairman and Director              May 19, 2000
----------------------------
James L. Clayton

/s/  Fred R. Lawson            President and Chief Executive      May 19, 2000
----------------------------   Officer (Principal Executive
Fred R. Lawson                 Officer)

/s/  C. David Allen            Chief Financial Officer and        May 19, 2000
----------------------------   Secretary (Principal
C. David Allen                 Financial Officer)

/s/  Scot M. Braun             Corporate Controller               May 19, 2000
----------------------------   (Principal Accounting Officer)
Scot M. Braun


                                      II-5
<PAGE>

/s/  C. Scott Mayfield, Jr.    Director                           May 19, 2000
----------------------------
C. Scott Mayfield, Jr.

/s/  C. Warren Neel            Director                           May 19, 2000
----------------------------
C. Warren Neel

/s/  Charles Earl Ogle, Jr.    Director                           May 19, 2000
----------------------------
Charles Earl Ogle, Jr.

/s/  W. David Sullins, Jr.     Director                           May 19, 2000
----------------------------
W. David Sullins, Jr.

/s/  L.A. Walker, Jr.          Director & Executive Vice          May 19, 2000
----------------------------   President of BankFirst
L.A. Walker, Jr.               Corporation

/s/  Geoffrey A. Wolpert       Director                           May 19, 2000
----------------------------
Geoffrey A. Wolpert


                                      II-6
<PAGE>

                                  EXHIBIT INDEX

Exhibit No.    Description
-----------    -----------

4.1            Amended and Restated Charter of BankFirst Corporation (previously
               filed as Exhibit 3.1 to the Company's Registration Statement on
               Form S-4 (Registration No. 333-52051) and incorporated herein by
               reference)

4.2            Bylaws of BankFirst Corporation (previously filed as Exhibit 3.2
               to the Company's Registration Statement on Form S-4 (Registration
               No. 333-52051) and incorporated herein by reference)

4.3*           BankFirst Corporation Stock Option Plan, as amended

5.1*           Opinion of Ritchie & Johnson, PLC as to the legality of the
               shares of common stock of the Company being registered

15.1*          Awareness Letter of Crowe, Chizek and Company LLP

23.1*          Consent of Ritchie & Johnson, PLC (included in Exhibit 5.1 to the
               Registration Statement)

23.2*          Consent of Crowe, Chizek and Company LLP

23.3*          Consent of G.R. Rush & Company, P.C.

24.1*          Power of Attorney (included on Signature Page)

--------------
*Filed herein.


                                      II-7