Middletown Township is in central Lower Bucks County, surrounding the boroughs of Langhorne, Langhorne Manor and Penndel, and including part of the community of Levittown. Middletown Friends Meeting was established in 1683, and the first Meeting House was built in 1690, near Neshaminy Creek, a mile west of Langhorne. Middletown is one of the five original townships in Bucks County, and was incorporated in 1692.

During the twentieth century, Middletown Township grew rapidly, as Route 1, Interstate 95, and the Amtrak rail system were developed, making it a convenient suburb of Philadelphia, central New Jersey and even New York City. Today it is one of the fastest-growing regions in Bucks County, encompassing the busy Oxford Valley Mall area. Despite its growth, the Township also is the site of Core Creek Park, a 1,200 acre public facility operated by the County's Parks and Recreation Department, where area residents can find solitude along the shores of Lake Luxembourg and the park's hiking, bicycling and horseback riding trails. Fisherman can try for bass, walleye, catfish, and bluegill, and boating enthusiasts can enjoy wind surfing, sailboating, and canoeing.