Geneseo is a city in Henry County, Illinois, United States. The population was 6,586 at the 2010 census, up from 6,480 in 2000. Geneseo is 20 miles east of the Quad Cities, at the intersection of Interstate 80, U.S. Route 6 and Illinois Route 82.Geneseo is well known for its Victorian-style architecture, quaint downtown, and its successful high school football and music programs.