Pennsylvania Route 24 (PA 24) is a 29-mile-long (47 km) state highway located within central Pennsylvania in the York County area. Its southern terminus is at the Mason–Dixon Line near Stewartstown, where PA 24 continues into Maryland as Maryland Route 23 (MD 23). The northern terminus is at PA 921 in Mount Wolf. The route heads north from the state line through rural areas in southern York County, intersecting PA 851 in Stewartstown and PA 216 in Winterstown. PA 24 continues north to Red Lion, where it crosses PA 74 and intersects the south end of PA 624. The route runs through suburban areas to the east of York, crossing PA 124, PA 462, and U.S. Route 30 (US 30). PA 24 continues north through rural land and reaches its end in Mount Wolf.