The Township of Chatham is a town in Barnstable County, Massachusetts, adjacent to Cape Cod. Its original name was Monomoit, an indigenous name for the area. The 2010 census recorded a population of 6,125. The town is also home to the Monomoy National Wildlife Refuge, and the Monomoy Theatre. The area is rich in history. The town was settled in 1640.
The township's boroughs include Avon-By-the-Sea, Belmar, Eatontown, and Middletown. Within the city limits are the communities of Chatham Twp, Manasquan, and Sea Girt. The township is also in Union County, which includes the towns of Berkeley Heights, East Windsor, and Mountain Lakes.