UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of report (Date of earliest event reported): April 27, 2017

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.

At the annual meeting of shareholders of each of Ameren Corporation (“Ameren”), Union Electric Company, doing business as Ameren Missouri (“Ameren Missouri”), and Ameren Illinois Company, doing business as Ameren Illinois (“Ameren Illinois”), held on April 27, 2017 (“Annual Meeting”), the matters listed below were submitted to a vote of each company’s respective shareholders.

Ameren

Item (1): Election of Directors

At Ameren’s Annual Meeting, the following individuals (comprising Ameren’s full Board of Directors) were elected:

Item (2): Non-Binding Advisory Approval of Executive Compensation

Item (3): Non-Binding Advisory Approval on Frequency of Executive Compensation Shareholder Advisory Vote

Based on these results, the Board of Directors has determined that Ameren will hold a non-binding advisory vote on the compensation of the Company’s named executive officers, as set forth in the Company’s proxy statement, every year.

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Item (4): Ratification of the Appointment of PricewaterhouseCoopers LLP as Independent Registered Public Accounting Firm for the Fiscal Year Ending December 31, 2017

Item (5): Shareholder Proposal Regarding a Report on Aggressive Renewable Energy Adoption

Item (6): Shareholder Proposal Regarding a Report on the Impact on the Company’s Generation Portfolio of Public Policies and Technological Advances that are Consistent with Limiting Global Warming

Item (7): Shareholder Proposal Regarding a Report on Coal Combustion Residuals

Ameren Missouri

Item (1): Election of Directors

At Ameren Missouri’s Annual Meeting, the following individuals (comprising Ameren Missouri’s full Board of Directors) were elected: Mark C. Birk, Fadi M. Diya, Martin J. Lyons, Jr., Michael L. Moehn, Gregory L. Nelson, and David N. Wakeman. Each individual received 102,123,834 votes for election and no withheld votes or broker non-votes.

Ameren Illinois

Item (1): Election of Directors

At Ameren Illinois’ Annual Meeting, the following individuals (comprising Ameren Illinois’ full Board of Directors) were elected: Martin J. Lyons, Jr., Richard J. Mark, Craig D. Nelson, Gregory L. Nelson, and David N. Wakeman. Each individual received 25,452,373 votes for election and no withheld votes or broker non-votes.

This combined Form 8-K is being filed separately by Ameren Corporation, Union Electric Company and Ameren Illinois Company (each a “registrant”). Information contained herein relating to any individual registrant has been filed by such registrant on its own behalf. No registrant makes any representation as to information relating to any other registrant.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, each registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized. The signature for each undersigned company shall be deemed to relate only to matters having reference to such company or its subsidiaries.

Date: May 1, 2017