Birmingham is a borough in Huntingdon County, Pennsylvania, United States. The population was 90 at the 2010 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.