Big Beaver is a borough in northern Beaver County, Pennsylvania, United States. The population was 1,852 at the 2020 census. It is a part of the Pittsburgh metropolitan area. The area was originally incorporated as Big Beaver Township in 1802, and was reincorporated as a borough in 1958.

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.