Sister cities of Upper Darby Township, Delaware County, Pennsylvania

Upper Darby Township is a home rule township bordering West Philadelphia in Delaware County, Pennsylvania, United States. Upper Darby is also home to the Tower Theater, a historic music venue on 69th street built in the 1920s. Upper Darby's population is diverse, representing over 100 ethnic cultures located within its densely populated, rowhouse streets. It is Pennsylvania's sixth most populous municipality.

Located just 2.8 miles from Center City (downtown Philadelphia), Upper Darby houses the western terminus of the Market-Frankford Line of the SEPTA mass transit system of Philadelphia, with the location at 69th street in the heart of Upper Darby's principal business district. Multiple trolley and bus lines connect the 69th Street Terminal to all major SEPTA lines of Philadelphia.

Upper Darby is 65% residential, 25% commercial, and 8% other. As of the 2010 census, the township had a total population of 82,795. Because of a home-rule charter adopted in 1974 and effective in 1976, Upper Darby utilizes a mayor-council form of management, unlike communities that are still under the Pennsylvania Township Code. ("First Class" townships in Pennsylvania have a board of commissioners divided into wards, and "Second Class" townships having a board of supervisors, which are usually elected "at-large".)