Amwell Township is an historic township established by a royal patent from Queen Anne in 1708. Its territory comprised 200 square miles and included present day Delaware Township, Raritan Township, Readington Township, East Amwell Township and West Amwell Township and portions of Clinton, Lebanon and Tewksbury Townships. In 1846, Amwell township was split into East and West Amwell and in 1954 a final adjustment was made to the two township's boundary lines.
Amwell township was located in the southeastern corner of Hunterdon County where it borders both Somerset and Mercer Counties. It included the unincorporated area of Ringoes, the oldest known settlement in Hunterdon County.