Knox -- U.S. County in Indiana Population (2000): 39256 Housing Units (2000): 17305 Land area (2000): 515.834254 sq. miles (1336.004527 sq. km) Water area (2000): 8.221806 sq. miles (21.294379 sq. km) Total area (2000): 524.056060 sq. miles (1357.298906 sq. km) Located within: Indiana (IN), FIPS 18 Location: 38.697416 N, 87.418937 W Headwords: Knox Knox, IN Knox County Knox County, IN