Horsham is a census-designated place in Horsham Township, Montgomery County, Pennsylvania, United States. The population was 15,193 at the 2020 census. It is home to the Biddle Air National Guard Base at the former site of Naval Air Station Joint Reserve Base Willow Grove.

Horsham Township is a home rule municipality in Montgomery County, Pennsylvania. It is located ten miles north of Center City Philadelphia. The township, incorporated in 1717, is one of the oldest original municipalities in Montgomery County. Although it retains the word "Township" in its official name, it has been governed by a Home Rule Charter since 1975 and is therefore not subject to the Pennsylvania Township Code. The population was 26,564 at the time of the 2020 census.