Marion is a city in Williamson and Johnson Counties, Illinois, United States, and is the county seat of Williamson County.[3] The population was 17,193 at the 2010 census. It is part of a dispersed urban area that developed out of the early 20th-century coal fields. Today Marion serves as the largest retail trade center in Southern Illinois with its central location along Interstate 57 and Illinois Route 13. It is home to the Illinois Star Centre mall and the Southern Illinois Miners baseball team. It was dubbed the “Hub of the Universe” by former mayor Robert L. Butler.

The city is part of the Marion-Herrin Micropolitan Area and is a part of the Carbondale-Marion-Herrin, Illinois Combined Statistical Area with 123,272 residents, the sixth most populous Combined statistical area in Illinois