Monaca is a borough in Beaver County, Pennsylvania, United States along the Ohio River, 25 miles (40 km) northwest of Pittsburgh. The population was 5,625 as of the 2020 census. First incorporated as Phillipsburg as the home of the New Philadelphia Society, its name was changed to Monaca in honor of the Native American Monacatootha. Fire clay is found in large quantities in the vicinity, and there is a Stoelzle Glass plant in the town.

Beaver County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 168,215. Its county seat is Beaver, and its largest city is Aliquippa. The county is part of the Greater Pittsburgh region of the state.