Kosciusko is a city in Attala County, Mississippi, United States. The population was 7,402 at the 2010 census. It is the county seat of Attala County. Kosciusko is located on the Natchez Trace Parkway, northeast of Jackson. It is named for the U.S. and Polish general Tadeusz Kościuszko, who assisted United States military efforts during the American Revolution. However, the Anglicized name of the city omits the "z".