Grand Tower is located in southern Illinois in Jackson County 15 miles southwest of Carbondale west of Highway 3 on the banks of the Mississippi River about 10 miles west of Cedar Lake. The town is named for the 80-foot tall block of galleon-shaped limestone, Tower Rock, nearby in the middle of the river. Other natural wonders in the area include Devil's Backbone & Devil's Bake Oven.
The population estimate for July 1, 1998 was 748, a decrease of 27 since 1990.