Oskaloosa is a city in and the county seat of Jefferson County, Kansas, United States. As of the 2010 census, the city population was 1,113. Oskaloosa is part of the Topeka, Kansas Metropolitan Statistical Area.
Oskaloosa is located at 39°12′57″N 95°18′50″W / 39.21583°N 95.31389°W / 39.21583; -95.31389 (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.
As of the census of 2000, there were 1,165 people, 439 households, and 291 families residing in the city. The population density was 1,281.5 people per square mile (494.3/km²). There were 478 housing units at an average density of 525.8 per square mile (202.8/km²). The racial makeup of the city was 98.03% White, 0.52% Native American, 0.69% from other races, and 0.77% from two or more races. Hispanic or Latino of any race were 1.97% of the population.