Souderton is a borough in Montgomery County, Pennsylvania. The population was 6,618 at the 2010 census. Souderton hosts the end of the annual Univest Grand Prix, a professional bicycle race. According to the United States Census Bureau, the borough has a total area of 1.1 square miles (2.9 km²), of which, 1.1 square miles (2.9 km²) of it is land and none of the area is covered with water. The terrain is mildly rolling hills, with some steeper hills in the downtown area, and flat terrain throughout.