Middletown High School serves 9th through 12th grade students in the Enlarged City School District of Middletown, which covers that city as well as adjacent portions of the towns of Wallkill and Wawayanda in Orange County, New York, United States. It is located on Gardner Avenue in a small outlying area of the city, near the county fairgrounds on a small rise south of NY 211.

Middletown is the largest city in Orange County, New York, United States. It lies in New York's Hudson Valley region, near the Wallkill River and the foothills of the Shawangunk Mountains. Middletown is situated between Port Jervis and Newburgh, New York. At the 2020 United States census, the city's population was 30,345, reflecting an increase of 2,259 from the 28,086 counted in the 2010 census. The ZIP Code is 10940. Middletown falls within the Kiryas Joel–Poughkeepsie–Newburgh Metropolitan Statistical Area, which belongs to the larger New York–Newark–Bridgeport, NY–NJ–CT–PA Combined Statistical Area.