Upper Darby Township, often shortened to Upper Darby, is a home rule township in Delaware County, Pennsylvania, United States. As of the 2020 census, the township had a total population of 85,681, making it the state's sixth most populated city or borough after Philadelphia, Pittsburgh, Allentown, Reading, and Erie. Upper Darby is 65% residential, 25% commercial, and 8% other. The township borders Philadelphia, the nation's sixth most populous city, with 1.6 million residents, and it is part of the Delaware Valley metropolitan area, the nation's seventh-largest metropolitan area, with 6.228 million people in the core metropolitan statistical area and 7.366 million in the combined statistical area as of 2020.
