Ellwood City is a borough primarily in Lawrence County, Pennsylvania, United States. With a small district extending into Beaver County, it lies along the Connoquenessing Creek just east of its confluence with the Beaver River. The population was 7,642 at the 2020 census. Ellwood City lies 30 miles (48 km) northwest of Pittsburgh and 8 miles (13 km) southeast of New Castle within the Pittsburgh metropolitan area.

Lawrence County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 86,070. The county seat and largest city is New Castle.