Center is a city in Ralls County, Missouri, United States. The population was 644 at the 2000 census. It is part of the Hannibal Micropolitan Statistical Area.
Center is located at 39°30′33″N 91°31′43″W / 39.50917°N 91.52861°W / 39.50917; -91.52861 (39.509267, -91.528566).
According to the United States Census Bureau, the city has a total area of 0.4 square miles (1.0 km²), all of it land.