Knox is a city in Center Township, Starke County, Indiana, United States. The population was 3,704 at the 2010 census. Knox is also within the Chicago Metropolitan Area along with the City of Valparaiso. The city is the county seat of Starke County. The city was founded in 1851 and is named after General Henry Knox. Knox was the home of two-time Indiana Governor Henry F. Schricker.
Knox is located at 41°17′39″N 86°37′21″W / 41.29417°N 86.6225°W / 41.29417; -86.6225 (41.294159, -86.622625), along the Yellow River.
According to the United States Census Bureau, the city has a total area of 3.9 square miles (10.2 km²), all of it land.