Grand Tower is a city in Jackson County, Illinois, United States. The population was 605 at the 2010 census. The town gets its name from Tower Rock, a landmark island in the Mississippi River.

Jackson County is a county located in the U.S. state of Illinois with a population of 52,974 at the 2020 census. Its county seat is Murphysboro, and its most populous city is Carbondale, home to the main campus of Southern Illinois University. The county was incorporated on January 10, 1816, and named for Andrew Jackson. The community of Brownsville served as the fledgling county's first seat.