Thomson is a village along Illinois Route 84 near the Mississippi River in Carroll County, Illinois, United States. The population was 590 at the 2010 census, up from 559 at the 2000 census. Just north of the village is the Thomson Correctional Center, a mostly-unused maximum security state prison.
Thomson is known for watermelons, and it has the nickname "Melon Capital of the World."
Thomson is located at 41°57?37?N 90°6?11?W / 41.96028°N 90.10306°W / 41.96028; -90.10306 (41.960168, -90.103152), about a mile (kilometer and a half) east of the Mississippi River in northwestern Illinois, 9 miles (14 km) northeast of Clinton, Iowa, 38 miles (61 km) northeast of Moline, Illinois in the Quad Cities, and 120 miles (190 km) west of Chicago.