Chatham is a town in Pittsylvania County, Virginia, United States. It is the county seat of Pittsylvania County. Chatham's population was 1,338 at the 2000 census. It is included in the Danville, Virginia Metropolitan Statistical Area.Chatham is home to Chatham High School and Hargrave Military Academy, the country's top rated military preparatory boarding school, which includes a special Colin Powell leadership program..