Lancaster is a city in Schuyler County, Missouri, in the United States. As of the 2010 census, the city population was 728. It is the county seat of Schuyler County.
Lancaster is part of the Kirksville Micropolitan Statistical Area.
Lancaster is located at 40°31′27″N 92°31′45″W / 40.52417°N 92.52917°W / 40.52417; -92.52917 (40.524087, -92.529190). According to the United States Census Bureau, the city has a total area of 1.5 square miles (3.9 km²), all of it land.