Pennsylvania's 16th congressional district is located in Northwestern Pennsylvania. It contains all of Erie County, Crawford County, Mercer County, Lawrence County, Butler County, and parts of Venango County. The district is represented by Republican Mike Kelly.

Erie County is a county in the Commonwealth of Pennsylvania. It is the northernmost county in Pennsylvania. As of the 2020 census, the population was 270,876. Its county seat is Erie. The county was created in 1800 and later organized in 1803. The county is part of the Northwest Pennsylvania region of the state.