<PAGE>   1

                                                            Registration No.


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

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

                             UNION ELECTRIC COMPANY
             (Exact name of registrant as specified in its charter)

            State of Missouri                                    43-0559760
 (State or other jurisdiction of incorporation                (I.R.S. Employer
             or organization)                                Identification No.)

                1901 Chouteau Avenue, St. Louis, Missouri  63103
         (Address, including zip code, of principal executive offices)

                             UNION ELECTRIC COMPANY
                        LONG-TERM INCENTIVE PLAN OF 1995
                            (Full title of the plan)

                    DONALD E. BRANDT, Senior Vice President
                          JAMES C. THOMPSON, Secretary
                1901 Chouteau Avenue, St. Louis, Missouri 63103
                                 (314) 621-3222

(Names, address, including zip code, and telephone number, including area code,
                            of agents for service)


                        CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>
- ---------------------------------------------------------------------------------------------------------
                                                      Proposed            Proposed
                                                       maximum             maximum
                                        Amount        offering           aggregate            Amount of
      Title of securities               to be          price              offering           registration
      to be registered                 registered     per share*           price                fee
- ---------------------------------------------------------------------------------------------------------
<S>                                 <C>               <C>               <C>                    <C>
Common Stock
  $5 par value, including
  related rights  . . . . . .       2,500,000 shares  $39.8125          $99,531,250            $34,321
- ---------------------------------------------------------------------------------------------------------
</TABLE>

* Calculated in accordance with Rule 457(h) on the basis of the average of the
  high and low prices of registrant's Common Stock reported in the consolidated
  reporting system on November 13, 1995.
<PAGE>   2

                                    PART II
              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.    INCORPORATION OF DOCUMENTS BY REFERENCE

        The following documents are incorporated in this registration statement
by reference:

(a)     Registrant's Annual Report on Form 10-K for the year ended December 31,
1994.

(b)     Registrant's Quarterly Reports on Form 10-Q for the quarters ended
March 31, 1995, June 30, 1995 (as amended by Forms 10-Q/A dated August 15, 1995
and September 7, 1995), and September 30, 1995.

(c)     Registrant's Current Report on Form 8-K dated June 12, 1995.

(d)     The information under the caption "Description of Common Stock" in the
Prospectus dated February 5, 1990, included in the Company's Registration
Statement Form S-8, Registration No. 33-32971, filed pursuant to the Securities
Act of 1933, as amended.

(e)     Registrant's proxy material forming a part of the Ameren Incorporated
Registration Statement on Form S-4  -  Registration Statement No.  33-64165.

All documents subsequently filed by the Registrant pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Securities Exchange Act of 1934, as amended, prior
to the filing of a post-effective amendment which indicates that all securities
offered have been sold or which deregisters all securities then remaining
unsold, shall be deemed to be incorporated by reference herein and to be a part
hereof from the date of the filing of such documents.


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 By-Laws of the Registrant provide that each person who now is or
hereafter becomes a director or officer shall be indemnified by the Registrant
to the maximum extent permitted by law against all judgments, expenses and
settlements incurred in connection with any direct or third party civil action
or any criminal claim against that person arising by reason of the fact that
the person is or was serving as a director or officer of the Registrant;
subject, however, to the statutory restriction that the Registrant cannot
indemnify any person if that person's conduct is adjudged to have been
knowingly fraudulent, deliberately dishonest or willful misconduct.  Partial
indemnification, to the extent permitted by law and public policy, is permitted
in instances where





                                     II - 1
<PAGE>   3

full indemnification is not permitted.  And, where full indemnification is
prohibited, such person nevertheless shall have a right of contribution to the
extent permitted by law and public policy in situations where said party is
held jointly liable with the Registrant.

        The aforesaid right to indemnification is not exclusive of any other
right to indemnification that such persons may be entitled under any contract
or agreement.  The Registrant has contracted with each director to provide
indemnification to the maximum extent permitted by law and public policy for
any and all expenses (including judgments, fines, attorneys' fees and amounts
paid in settlement) incurred by said director in his capacity as a director.

        Section 351.355, RSMo., also provides for indemnification by a
corporation of each director and officer in connection with any civil or
criminal action unless said person's conduct is adjudged to have been knowingly
fraudulent, deliberately dishonest or willful misconduct.

        Subject to certain exceptions, the directors and officers of the
Registrant are insured for loss up to $25,000,000 resulting from any claim or
claims made against them, including claims arising under the Securities Act of
1933 and caused by any negligent act, any error, any omission or any breach of
duty while acting in their capacities as officers or directors, and the
Registrant is identically insured to the extent that it shall have indemnified
the directors and officers for such loss (subject to a deductible of $2,000,000
with respect to each loss).  The premiums for such insurance are paid by the
Registrant.


ITEM 7.    EXEMPTIONS FROM REGISTRATION CLAIMED

        Not Applicable.


ITEM 8.    EXHIBITS

  Exhibit No.


       23   Consent of Independent Accountants.


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 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





                                     II - 2
<PAGE>   4

                    information set forth in the registration statement;
                    notwithstanding the foregoing, any increase or decrease in
                    volume of securities offered (if the total dollar value of
                    securities offered would not exceed that which was
                    registered) and any deviation from the low or high end of
                    the estimated maximum offering range may be reflected in the
                    form of prospectus filed with the Securities and Exchange
                    Commission pursuant to Rule 424(b) if, in the aggregate, the
                    changes in volume and price represent no more than a 20%
                    change in the maximum aggregate offering price set forth in
                    the "Calculation of Registration Fee" table in the effective
                    registration statement;

              (iii) To include any material information with respect to
                    the plan of distribution not 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, Form S-8 or Form F-3, and the
information required to be included in a post-effective amendment by those
paragraphs is contained in periodic reports filed by the registrant pursuant to
Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are
incorporated by reference in the registration statement.

        (2)   That, for the purpose of determining any liability under the
Securities Act of 1933, 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 of 1933, each filing of the
registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Securities Exchange Act of 1934 (and, where applicable, each filing of an
employee benefit plan's annual report pursuant to Section 15(d) of the
Securities Exchange Act of 1934) 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.

        Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to directors, officers and controlling persons of
the Registrant pursuant to the foregoing provisions, or otherwise, the
Registrant 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
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 Act and
will be governed by the final adjudication of such issue.





                                     II - 3
<PAGE>   5

                                   SIGNATURES

        The Registrant.  Pursuant to the requirements of the Securities Act of
1933, 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 St. Louis, and State of Missouri, on
the 17th day of November, 1995.

                                           UNION ELECTRIC COMPANY
                                                (Registrant)


                                           /s/ DONALD E. BRANDT          
                                           ------------------------
                                               DONALD E. BRANDT
                                             Senior Vice President


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



/s/ C. W. MUELLER                         /s/ RICHARD A. LIDDY            
- ---------------------------------         --------------------------------
C. W. Mueller                             Richard A. Liddy, Director
President, Chief Executive Officer   
and Director                         
(Principal Executive Officer)                                               
                                          ----------------------------------
                                          John Peters MacCarthy, Director
                                     
/s/ DONALD E. BRANDT                 
- ---------------------------------     
Donald E. Brandt                          /s/ PAUL L. MILLER, JR.           
Senior Vice President                     ----------------------------------
(Principal Financial and                  Paul L. Miller, Jr., Director
Accounting Officer)                  
                                          /s/ ROBERT H. QUENON           
                                          ----------------------------------
                                          Robert H. Quenon, Director
/s/ WILLIAM E. CORNELIUS             
- ---------------------------------      
William E. Cornelius, Director       
                                          /s/ HARVEY SALIGMAN          
                                          ----------------------------------
                                          Harvey Saligman, Director
/s/ THOMAS A. HAYS                   
- ---------------------------------    
Thomas A. Hays, Director             
                                                                            
                                          ----------------------------------
                                          Janet McAfee Weakley, Director
/s/ THOMAS H. JACOBSEN               
- ---------------------------------       
Thomas H. Jacobsen, Director         





                                     II - 4
<PAGE>   6


                                 EXHIBIT INDEX

Exhibit          Description

  23             Consent of Independent Accountants.



              All Exhibits are filed electronically with Form S-8.





                                     II - 5
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{"company-data": {"conformed-name": "UNION ELECTRIC CO", "cik": "0000100826", "assigned-sic": "4911", "irs-number": "430559760", "state-of-incorporation": "MO", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "033-64359", "film-number": "95594456"}, "business-address": {"street1": "P O BOX 149", "city": "ST LOUIS", "state": "MO", "zip": "63166", "phone": "3146213222"}, "mail-address": {"street1": "P O BOX 149", "city": "ST LOUIS", "state": "MO", "zip": "63166"}}
1

                                                            Registration No.

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

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

                             UNION ELECTRIC COMPANY
             (Exact name of registrant as specified in its charter)

            State of Missouri                                    43-0559760
 (State or other jurisdiction of incorporation                (I.R.S. Employer
             or organization)                                Identification No.)

                1901 Chouteau Avenue, St. Louis, Missouri  63103
         (Address, including zip code, of principal executive offices)

                             UNION ELECTRIC COMPANY
                        LONG-TERM INCENTIVE PLAN OF 1995
                            (Full title of the plan)

                    DONALD E. BRANDT, Senior Vice President
                          JAMES C. THOMPSON, Secretary
                1901 Chouteau Avenue, St. Louis, Missouri 63103
                                 (314) 621-3222

(Names, address, including zip code, and telephone number, including area code,
                            of agents for service)

                        CALCULATION OF REGISTRATION FEE
- ---------------------------------------------------------------------------------------------------------
                                                      Proposed            Proposed
                                                       maximum             maximum
                                        Amount        offering           aggregate            Amount of
      Title of securities               to be          price              offering           registration
      to be registered                 registered     per share*           price                fee
- ---------------------------------------------------------------------------------------------------------
Common Stock
  $5 par value, including
  related rights  . . . . . .       2,500,000 shares  $39.8125          $99,531,250            $34,321
- ---------------------------------------------------------------------------------------------------------
* Calculated in accordance with Rule 457(h) on the basis of the average of the
  high and low prices of registrant's Common Stock reported in the consolidated
  reporting system on November 13, 1995.
2

                                    PART II
              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.    INCORPORATION OF DOCUMENTS BY REFERENCE

        The following documents are incorporated in this registration statement
by reference:

(a)     Registrant's Annual Report on Form 10-K for the year ended December 31,
1994.

(b)     Registrant's Quarterly Reports on Form 10-Q for the quarters ended
March 31, 1995, June 30, 1995 (as amended by Forms 10-Q/A dated August 15, 1995
and September 7, 1995), and September 30, 1995.

(c)     Registrant's Current Report on Form 8-K dated June 12, 1995.

(d)     The information under the caption "Description of Common Stock" in the
Prospectus dated February 5, 1990, included in the Company's Registration
Statement Form S-8, Registration No. 33-32971, filed pursuant to the Securities
Act of 1933, as amended.

(e)     Registrant's proxy material forming a part of the Ameren Incorporated
Registration Statement on Form S-4  -  Registration Statement No.  33-64165.

All documents subsequently filed by the Registrant pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Securities Exchange Act of 1934, as amended, prior
to the filing of a post-effective amendment which indicates that all securities
offered have been sold or which deregisters all securities then remaining
unsold, shall be deemed to be incorporated by reference herein and to be a part
hereof from the date of the filing of such documents.

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 By-Laws of the Registrant provide that each person who now is or
hereafter becomes a director or officer shall be indemnified by the Registrant
to the maximum extent permitted by law against all judgments, expenses and
settlements incurred in connection with any direct or third party civil action
or any criminal claim against that person arising by reason of the fact that
the person is or was serving as a director or officer of the Registrant;
subject, however, to the statutory restriction that the Registrant cannot
indemnify any person if that person's conduct is adjudged to have been
knowingly fraudulent, deliberately dishonest or willful misconduct.  Partial
indemnification, to the extent permitted by law and public policy, is permitted
in instances where

                                     II - 1
3

full indemnification is not permitted.  And, where full indemnification is
prohibited, such person nevertheless shall have a right of contribution to the
extent permitted by law and public policy in situations where said party is
held jointly liable with the Registrant.

        The aforesaid right to indemnification is not exclusive of any other
right to indemnification that such persons may be entitled under any contract
or agreement.  The Registrant has contracted with each director to provide
indemnification to the maximum extent permitted by law and public policy for
any and all expenses (including judgments, fines, attorneys' fees and amounts
paid in settlement) incurred by said director in his capacity as a director.

        Section 351.355, RSMo., also provides for indemnification by a
corporation of each director and officer in connection with any civil or
criminal action unless said person's conduct is adjudged to have been knowingly
fraudulent, deliberately dishonest or willful misconduct.

        Subject to certain exceptions, the directors and officers of the
Registrant are insured for loss up to $25,000,000 resulting from any claim or
claims made against them, including claims arising under the Securities Act of
1933 and caused by any negligent act, any error, any omission or any breach of
duty while acting in their capacities as officers or directors, and the
Registrant is identically insured to the extent that it shall have indemnified
the directors and officers for such loss (subject to a deductible of $2,000,000
with respect to each loss).  The premiums for such insurance are paid by the
Registrant.

ITEM 7.    EXEMPTIONS FROM REGISTRATION CLAIMED

        Not Applicable.

ITEM 8.    EXHIBITS

  Exhibit No.

       23   Consent of Independent Accountants.

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 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

                                     II - 2
4

                    information set forth in the registration statement;
                    notwithstanding the foregoing, any increase or decrease in
                    volume of securities offered (if the total dollar value of
                    securities offered would not exceed that which was
                    registered) and any deviation from the low or high end of
                    the estimated maximum offering range may be reflected in the
                    form of prospectus filed with the Securities and Exchange
                    Commission pursuant to Rule 424(b) if, in the aggregate, the
                    changes in volume and price represent no more than a 20%
                    change in the maximum aggregate offering price set forth in
                    the "Calculation of Registration Fee" table in the effective
                    registration statement;

              (iii) To include any material information with respect to
                    the plan of distribution not 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, Form S-8 or Form F-3, and the
information required to be included in a post-effective amendment by those
paragraphs is contained in periodic reports filed by the registrant pursuant to
Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are
incorporated by reference in the registration statement.

        (2)   That, for the purpose of determining any liability under the
Securities Act of 1933, 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 of 1933, each filing of the
registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Securities Exchange Act of 1934 (and, where applicable, each filing of an
employee benefit plan's annual report pursuant to Section 15(d) of the
Securities Exchange Act of 1934) 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.

        Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to directors, officers and controlling persons of
the Registrant pursuant to the foregoing provisions, or otherwise, the
Registrant 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
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 Act and
will be governed by the final adjudication of such issue.

                                     II - 3
5

                                   SIGNATURES

        The Registrant.  Pursuant to the requirements of the Securities Act of
1933, 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 St. Louis, and State of Missouri, on
the 17th day of November, 1995.

                                           UNION ELECTRIC COMPANY
                                                (Registrant)

                                           /s/ DONALD E. BRANDT          
                                           ------------------------
                                               DONALD E. BRANDT
                                             Senior Vice President

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

/s/ C. W. MUELLER                         /s/ RICHARD A. LIDDY            
- ---------------------------------         --------------------------------
C. W. Mueller                             Richard A. Liddy, Director
President, Chief Executive Officer   
and Director                         
(Principal Executive Officer)                                               
                                          ----------------------------------
                                          John Peters MacCarthy, Director
                                     
/s/ DONALD E. BRANDT                 
- ---------------------------------     
Donald E. Brandt                          /s/ PAUL L. MILLER, JR.           
Senior Vice President                     ----------------------------------
(Principal Financial and                  Paul L. Miller, Jr., Director
Accounting Officer)                  
                                          /s/ ROBERT H. QUENON           
                                          ----------------------------------
                                          Robert H. Quenon, Director
/s/ WILLIAM E. CORNELIUS             
- ---------------------------------      
William E. Cornelius, Director       
                                          /s/ HARVEY SALIGMAN          
                                          ----------------------------------
                                          Harvey Saligman, Director
/s/ THOMAS A. HAYS                   
- ---------------------------------    
Thomas A. Hays, Director             
                                                                            
                                          ----------------------------------
                                          Janet McAfee Weakley, Director
/s/ THOMAS H. JACOBSEN               
- ---------------------------------       
Thomas H. Jacobsen, Director         

                                     II - 4
6

                                 EXHIBIT INDEX

Exhibit          Description

  23             Consent of Independent Accountants.

              All Exhibits are filed electronically with Form S-8.

                                     II - 5