费城县 (Philadelphia County, Pennsylvania)是美国宾夕法尼亚州东南部的一个县，东南隔特拉华河与新泽西州为邻。面积369平方公里。根据美国2000年人口普查，共有人口1,517,550。县治费城 (自1854年起已无分区，县市同界。1952年起已无县政府，但该州适用于县的法律仍然有效)。

成立于1682年11月，是本州最早的三个县之一 (另外两个为切斯特县和巴克斯县)。县名来自小亚细亚的Philadelphus，意思是「兄弟之爱」。

Philadelphia County is a county located in the commonwealth of Pennsylvania. At the 2010 census, the population was 1,526,006, making it the most populous county in the state, despite being the second smallest county in the state by land area. Philadelphia County is one of the three original counties, along with Chester and Bucks counties, created by William Penn in November 1682. Since 1854, the county has been coterminous with the city of Philadelphia, which also serves as its seat. It is the most populous county in the United States coterminous with a municipality.