Oil City is the largest city in Venango County, Pennsylvania, United States. Known for its prominence in the initial exploration and development of the petroleum industry, it is located at a bend in the Allegheny River at the mouth of Oil Creek. The population was 9,608 at the 2020 census, and it is the principal city of the Oil City micropolitan area.

Venango County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 50,454. Its county seat is Franklin. The county was created in 1800 and later organized in 1805. The county is part of the Northwest Pennsylvania region of the state.