Ridley Park is a borough in Delaware County, Pennsylvania, United States. The population was 7,002 at the 2010 census. Ridley Park is the home of Boeing's CH-47 Chinook helicopter division.

Delaware County, colloquially referred to as Delco, is a county in the Commonwealth of Pennsylvania. With a population of 576,830 as of the 2020 census, it is the fifth-most populous county in Pennsylvania and the third-smallest in area. The county was created on September 26, 1789, from part of Chester County and named for the Delaware River. The county is part of the Southeast Pennsylvania region of the state.