Kewanee is a city in Henry County, Illinois, United States. "Kewanee" is the Winnebago word for prairie chicken, which lekked there. The population was 12,916 at the 2010 census, down from 12,944 at the 2000 census.
Kewanee is located at 41°14′28″N 89°55′32″W / 41.24111°N 89.92556°W / 41.24111; -89.92556 (41.241180, -89.925680).
According to the United States Census Bureau, the city has a total area of 6.3 square miles (16.3 km²), of which, 6.3 square miles (16.3 km²) of it is land and 0.16% is water.