The First Missouri State Capitol State Historic Site is a state-owned property in St. Charles, Missouri, preserving the building that served as Missouri's capitol from 1821 to 1826. The site is part of the St. Charles Historic District in the city's Riverfront neighborhood. It was acquired by the state in 1960 and was added to the National Register of Historic Places in 1969.
The First Missouri State Capitol Buildings consists of four connected brick buildings. They are one room deep with gabled roofs and stone foundations. The first floor of the building was used as a store and residence while the second floor was used by the state government. Both are preserved today.