Clayton is a town in Johnston County, North Carolina, United States. A very small portion of the town extends into Wake County. As of 2010, Clayton's population was 9,676 people. Since 2000, it had a population growth of 38.80 percent. Much of that growth can be attributed to the town's close proximity to the Research Triangle area and access to major highways such as I-40, U.S. 70, and NC 42.In 2006, construction began on the Highway 70 Clayton Bypass, a 10.5-mile stretch from Interstate 40 along the southern portion of Clayton to Highway 70 business in Smithfield. It was completed in June 2008.The Town Hall is located at 111 East Second Street in Downtown Clayton. The Town Hall complex is shared with The Clayton Center Auditorium and Conference Center.