Mercer County, Missouri

Mercer County
Mercer County Courthouse and downtown Princeton
Location within the U.S. state of Missouri
Missouri's location within the U.S.
Coordinates: 40°25′N 93°34′W / 40.42°N 93.57°W / 40.42; -93.57
Country United States
State Missouri
FoundedFebruary 14, 1845
Named afterJohn Francis Mercer
SeatPrinceton
Largest cityPrinceton
Area
  Total
455 sq mi (1,180 km2)
  Land454 sq mi (1,180 km2)
  Water1.3 sq mi (3 km2)  0.3%
Population
 (2020)
  Total
3,538
  Estimate 
(2024)
3,452
  Density7.6/sq mi (2.9/km2)
Time zoneUTC−6 (Central)
  Summer (DST)UTC−5 (CDT)
Congressional district6th

Mercer County is a county located in the northwestern portion of the U.S. state of Missouri. As of the 2020 census, the population was 3,538, making it the second-least populous county in Missouri. Its county seat is Princeton. The county was organized February 14, 1845, and named for General John F. Mercer of the Revolutionary War.