Mo. Rev. Stat. § 115.167

115.167. Change of name of registered voter, procedure for. — If a registered voter obtains a lawful name change, including a change because of marriage, the voter shall notify the election authority of such change and the election authority shall, upon notification, enter the change on the voter's registration cards. After filling in the voter's new name and transferring other necessary information from the voter's previous registration cards to a new set of cards, the election authority may send new cards to the voter for signature or may require the voter to sign new cards at the polls. If the election authority does require the voter to sign new cards, the new cards shall become the voter's official registration cards. A registered voter who obtains a lawful name change may, after notifying the election judges of the name change, vote at one election under the previous name. The election judges shall notify the election authority of the voter's name change and the election authority shall enter the change on the voter's registration cards as provided for in this section.

(L. 1977 H.B. 101 § 7.105, A.L. 1983 S.B. 234, A.L. 1988 H.B. 933, et al., A.L. 1993 S.B. 31)