Eddystone is a borough in Delaware County, Pennsylvania, United States. The population was 2,442 at the 2000 census.
The area at the mouth of Ridley Creek was first called "Tequirassy" by Native Americans. The land was owned by Olof Persson Stille, one of the early settlers from New Sweden, who had immigrated in 1641. Olof Stille, a millwright by trade, came from Penningby Manor in Länna in the county of Uppland, north of Stockholm, Sweden. After the conquest of the colony by the Dutch in 1658, Stille was one of the four commissaries or magistrates appointed to administer justice among the inhabitants, and thus became a judge of the first court on the banks of the Delaware.
The Borough of Eddystone was formed around the Eddystone Print Works. William Simpson & Sons established the Eddystone Print Works on the land that is now Eddystone in October 1873, after the land on which their previous factory had operated was condemned to make way for Fairmount Park.