Pennsylvania Route 427 (PA 427) is an 10-mile (16 km) long state highway located in Venango and Crawford counties in Pennsylvania. The southern terminus is at US 322 in Sugarcreek. The northern terminus is at PA 27 near Bradleytown.

PA 427 begins at an intersection with US 322 in Sugarcreek, Venango County, heading northwest on a two-lane undivided road. The route parallels US 322 before turning north past a few rural homes. The road heads northeast into farmland, turning east before curving north into wooded areas, running to the east of Sugar Creek. PA 427 turns west to cross the creek, curving north into agricultural areas with some woods and residences. The route continues into Jackson Township and turns northeast to cross Sugar Creek again before making another curve to the north. The road heads into Cooperstown and becomes South Main Street, heading into residential areas and turning northeast to run along the east bank of Sugar Creek. PA 427 turns west onto Factory Street and crosses the creek prior to heading northwest onto North Main Street and passing a few businesses. The route turns north onto Academy Street and runs between homes the west and the Sugar Creek to the east, curving to the northeast. The road becomes Bradleytown Road as it heads back into Jackson Township and runs north through open farmland with occasional residences. PA 427 continues through areas of farms and woods as it passes through Plum Corners. The road heads into more wooded areas with some farm fields as it crosses into Plum Township and turns to the northeast. The route crosses Sugar Creek again and comes to Bradleytown, where it turns north to remain along Bradleytown Road. PA 427 heads through more agricultural areas with some woods and homes, crossing the creek. The route enters Troy Township in Crawford County and immediately ends at PA 27.