| Missouri Republican Party | |
| Colorcode: |
|
| Colors: | Red |
| Headquarters: | Jefferson City, Missouri |
| Leader1 Title: | Chairperson |
| Leader1 Name: | Nick Myers |
| Leader2 Title: | Governor |
| Leader2 Name: | Mike Parson |
| Leader3 Title: | Lieutenant Governor |
| Leader3 Name: | Mike Kehoe |
| Leader4 Title: | Senate President (pro tempore) |
| Leader4 Name: | Caleb Rowden |
| Leader5 Title: | House Speaker |
| Leader5 Name: | Dean Plocher |
| National: | Republican Party |
| Seats1 Title: | U.S. Senate Seats |
| Seats2 Title: | U.S. House Seats |
| Seats3 Title: | Statewide Executive Offices |
| Seats5 Title: | Seats in the Missouri Senate |
| Seats6 Title: | Seats in the Missouri House of Representatives |
| State: | Missouri |
The Missouri Republican Party is the affiliate of the United States Republican Party in Missouri. Its chair is Nick Myers, who has served since 2021. It is currently the dominant party in the state, controlling the majority of Missouri's U.S. House seats, both U.S. Senate seats, both houses of the state legislature, and all statewide offices, including the governorship.
Francis Preston Blair Jr. was the only Republican member of congress from a border state at the beginning of the American Civil War. However, he proposed that the state party instead merge with the Missouri Unionist Party.
Blair and other Unionists in Missouri supported the removal of John C. Frémont's military command and the rescinding of his emancipation order. However, B. Gratz Brown, the former chair, supported Frémont. Blair and Brown disagreed on gradual compensated emancipation and slave colonization with Blair in support and Brown in opposition.
The Radical Republicans, including Brown, held a separate convention in 1864. They sent an uncommitted delegation to the 1864 National Union National Convention which was seated. Brown wanted to send a delegation to Frémont's Radical Democracy convention. This delegation was the only one to vote against Lincoln.
The Radical wrote the state constitution in 1865, which emancipated slaves while Blair returned to the Democratic Party.
Members of the party left to form the Liberal Republican Party. Brown, their gubernatorial nominee, won the 1870 election.