Oil Creek is a 46.7-mile (75.2 km) tributary of the Allegheny River that is located in Venango and Crawford counties in the Commonwealth of Pennsylvania in the United States.

The Allegheny River is a 325-mile-long (523 km) headwater stream of the Ohio River that is located in western Pennsylvania and New York in the United States. It runs from its headwaters just below the middle of Pennsylvania's northern border, northwesterly into New York, then in a zigzag southwesterly across the border and through Western Pennsylvania to join the Monongahela River at the Forks of the Ohio at Point State Park in Downtown Pittsburgh, Pennsylvania.