Illinois City is an unincorporated community in the U.S. state of Illinois, across the Mississippi River from Muscatine, Iowa.

[2] It straddles Buffalo Prairie Township and Drury Township in Rock Island County, Illinois.

[3] As of 2014[update], a United States Post Office, ZIP Code 61259,[4] remains open at 23828 124th Avenue West.

Illinois City first appeared as a census designated place in the 2020 U.S.

This Rock Island County, Illinois location article is a stub.