Knox -- U.S. County in Missouri Population (2000): 4361 Housing Units (2000): 2317 Land area (2000): 505.706984 sq. miles (1309.775019 sq. km) Water area (2000): 1.066762 sq. miles (2.762900 sq. km) Total area (2000): 506.773746 sq. miles (1312.537919 sq. km) Located within: Missouri (MO), FIPS 29 Location: 40.136849 N, 92.147931 W Headwords: Knox Knox, MO Knox County Knox County, MO