Grafton is the oldest city in Jersey County, Illinois, United States. It is located near the confluence of the Illinois and Mississippi Rivers. As of the 2010 U.S. census, the city had a total population of 674. Prior to the Great Flood of 1993, Grafton had enjoyed a stable population of nearly 1,000 residents. The city's current mayor is Tom Thompson. Grafton is a part of the Metro-East region and the St. Louis Metropolitan Statistical Area.