Pennsylvania Route 412 (PA 412) is a 17.75-mile-long (28.57 km) north–south state route located in Northampton and Bucks counties in southeastern Pennsylvania. Its southern terminus is at PA 611 in the Nockamixon Township community of Harrow. Its northern terminus is at PA 378 in Bethlehem. The route passes through rural areas in northern Bucks County, forming a concurrency with PA 212 in the Springtown area. From there, PA 412 continues into Northampton County and passes through Hellertown before coming to an interchange with Interstate 78 (I-78) and heading into Bethlehem. In Bethlehem, PA 412 passes the former Bethlehem Steel site and runs through the South Side neighborhood.