Woodlyn is a census-designated place (CDP) in Delaware County, Pennsylvania, United States. The population was 9,485 at the 2010 census, down from 10,036 at the 2000 census. It is a part of Ridley Township, and children residing within the community generally attend schools in the Ridley School District. Woodlyn is served by the Woodlyn Fire Co. for fire, rescue and EMS services.
Woodlyn is located in the western part of Ridley Township. It is bordered to the northeast by the Folsom part of Ridley Township, to the east by the borough of Ridley Park, to the south by the borough of Eddystone, to the southwest by the city of Chester, to the west by Nether Providence Township, and to the north by Springfield Township and the borough of Swarthmore. Interstate 476 (the Blue Route) and Interstate 95 intersect in the southern part of Woodlyn. Center City, Philadelphia, is 14 miles (23 km) to the northeast via I-95.
According to the United States Census Bureau, the Woodlyn CDP has a total area of 1.7 square miles (4.3 km2), all of it land.
At the 2000 census there were 10,036 people, 3,960 households, and 2,637 families in the CDP. The population density was 6,100.8 people per square mile (2,348.4/km2).