is a city in Jefferson County, Kansas, United States. The population was 1,165 at the 2000 census. It is the county seat of Jefferson County.
Oskaloosa is located at (39.215849, -95.313800). It is at the intersection of U.S. Route 59 and K-92, approximately 15 miles north of Lawrence.
According to the United States Census Bureau, the city has a total area of 0.9 square miles (2.4 km²), all of it land.