Pennsylvania Route 331 (PA 331) is a 14.5-mile-long (23.3 km), east–west state highway located in Washington County, Pennsylvania. The western terminus is at the West Virginia state line in Independence Township where the road continues as West Virginia Route 67. The eastern terminus is at PA 844 in Canton Township. PA 331 was initially established by the 1940s. The route was rerouted in the 2000s following the closure of a bridge over Buffalo Creek.