Mo. Rev. Stat. § 77.250: Mayor to be president of council — vote.

The mayor shall be president of the council and shall preside over same, but shall not vote except in case of a tie in said council, when he shall cast the deciding vote; but provided, however, that he shall have no such power to vote in cases when he is an interested party. He shall have the superintending control of all the officers and affairs of the city, and shall take care that the ordinances of the city and the state laws relating to such city are complied with.