Immanuel on the Green (Episcopal) is an historic church in New Castle, Delaware, listed as a contributing property in the New Castle Historic District. The church is situated near the center of New Castle at the northeast end of the Green, or town common, making it a prominent local landmark and tourist attraction. Operating continuously since 1689, it is the oldest Anglican parish in Delaware and the oldest continuously operating Anglican/Episcopal parish in the country. The church building was constructed between 1703 and 1708 and enlarged in 1822. The interior and roof were rebuilt following a disastrous fire in 1980.

New Castle is a city in New Castle County, Delaware, United States. The city is located six miles (10 km) south of Wilmington and is situated on the Delaware River. As of 2020, the city's population was 5,551. New Castle constitutes part of the Delaware Valley or Philadelphia metropolitan area.