Adelphia is an unincorporated community located in northern Howell Township, Monmouth County, in the U.S. state of New Jersey.

[6] The community of Adelphia has a total area of 35.41 square kilometres (13.67 sq mi) and an estimated population of 17,000.

[8] Adelphia is also the home of the Talmudical Academy of Central New Jersey, an Orthodox Jewish yeshiva high school and rabbinical college.

The Howell Park & Ride, located in the neighborhood of Adelphia off of U.S. Route 9, is utilized by many commuters.

[12] The climate in this area is characterized by hot, humid summers and generally mild to cool winters.