Birmingham is a borough in Huntingdon County, Pennsylvania, United States. The population was 90 at the 2020 census. Birmingham is the site of the Birmingham Window, a geologic structure created by a Paleozoic thrust fault. Birmingham's early settler, John Cadwallader, settled on a hill above the Little Juniata River and made plans to establish a large city. Legend among the local residents is that it was once in consideration to be the state capital. In the first several decades of the 19th century, the village grew quickly as a hub for commerce being carried on the Little Juniata River and on the nearby Pennsylvania Canal. By 1850, the Pennsylvania Railroad had passed through the valley. The development of the railroad diminished the importance of Birmingham as a trading hub since the railroad's nearby hubs in Tyrone and Altoona grew quickly on land that was better suited for development.

Huntingdon County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 44,092. Its county seat is Huntingdon. The county was created on September 20, 1787, mainly from the northern part of Bedford County, plus an addition of territory on the east from Cumberland County. The county is part of the Southwest Pennsylvania region of the state.