Pennsylvania Route 861 (PA 861) is a 11.67-mile-long (18.78 km) state highway located in Clarion County in Pennsylvania.

PA 861 begins at an intersection with PA 68 in the borough of Rimersburg, heading southeast on a two-lane undivided road.

The road curves south, passing through Diamond before making a turn to the east and continuing into agricultural areas.

PA 861 enters Porter Township and continues east through a mix of farmland and woodland with occasional homes.

The route heads to the southeast through more rural areas before curving east and heading into the borough of New Bethlehem.