Columbia, Illinois

Columbia is a city mainly in Monroe County with a small portion in St. Clair County in the U.S. state of Illinois, about 12 miles (19 km) south of St. Louis, Missouri. The population was 9,707 at the 2010 census.

Columbia High School is a public high school in Columbia, Illinois. It is part of Columbia Community Unit School District 4.

The Gundlach-Grosse House is a historic house located at 625 N. Main St. in Columbia, Illinois. The Greek Revival house was built in 1857 for German immigrants John and Philip Peter Gundlach. The brothers ran a local brewery which remained in their family for four generations, and John Gundlach served as Columbia's mayor for four years.