Waltonville is a village in Jefferson County, Illinois, United States. The population was 434 at the 2010 census. It is part of the Mount Vernon Micropolitan Statistical Area.
There were a series of small settlements near Waltonville prior to its formation. In 1840, Eli Gilbert dammed Rayse Creek about a mile northeast of Waltonville, near the point where the Mt. Vernon/Pinckneyville road crossed the creek. He built a saw mill, grist mill and store at this location, which was called "Mill Town". In 1860, Knob Creek Post Office was opened there. This was in McClellan Township.
In 1867, a settlement called Williamsburg was started, about a half mile west of Mill Town.