Missouri Senate
The Missouri Senate is the upper chamber of the Missouri General Assembly. It has 34 members, representing districts with an average population of 174,000. Its members serve four-year terms, with half the seats being up for election every two years. The Senate chooses a President Pro-tem to serve in the absence of the Lieutenant Governor or when he shall have to exercise the office of Governor of the State of Missouri if there is a vacancy in that office due to death, resignation, impeachment, or incapacitation. The Missouri State Congressional Term Limits Amendment, also known as Amendment 12, was on the November 3, 1992 ballot in Missouri as an initiated constitutional amendment, where it was approved. The measure amended the Constitution to prohibit a person from serving more than eight years in either the state house of representatives or state senate, or a total of sixteen years in both houses.
Composition
After the 2018 general election the party representation in the Senate was:Senate officers
| Position | Name | Party | Residence | District |
| President Pro Tem of the Senate | Dave Schatz | Republican | Sullivan | 26 |
| Majority Leader | Caleb Rowden | Republican | Columbia | 19 |
| Assistant Majority Floor Leader | Wayne Wallingford | Republican | Cape Girardeau | 27 |
| Minority Leader | Gina Walsh | Democratic | Bellefontaine Neighbors | 13 |