Ridley Township is a township in Delaware County, Pennsylvania, United States. The population was 30,768 at the 2010 census. Ridley Township contains the (CDPs) of Folsom and Woodlyn, along with the unincorporated communities of Crum Lynne and Holmes and a portion of Secane.

Pennsylvania Route 291 is an east–west state route in Pennsylvania that runs from U.S. Route 13 and US 13 Business in Trainer, Delaware County, east to Interstate 76 (I-76) in South Philadelphia near the Walt Whitman Bridge and the South Philadelphia Sports Complex. Except for a short 1-mile (1.6 km) section between the western terminus and the Chester/Trainer line, PA 291 is mostly a four-lane highway. From the western terminus to the eastern part of Chester, the route has a concurrency with US 13. It runs parallel to the Delaware River for much of the route. The route passes through industrial areas near the river in Delaware County, serving Chester, Eddystone, Essington, and Lester. PA 291 enters Philadelphia near the Philadelphia International Airport, at which point it has an interchange with I-95. The route crosses the Schuylkill River on the George C. Platt Memorial Bridge and continues along Penrose Avenue to I-76. It has been designated the Industrial Heritage Highway.