Pennsylvania Route 512 is a 26-mile (42 km) long state route in eastern Pennsylvania. The southern terminus is at U.S. Route 22 north of Bethlehem in Hanover Township. The northern terminus is at Pennsylvania Route 611 in Upper Mount Bethel Township.

PA 512 begins at an interchange with U.S. Route 22 in Hanover Township. PA 512 continues north through Hanover Township as Bath Pike. Once the route enters East Allen Township, PA 512 is known as Beth Bath Pike. In Bath, PA 512 becomes Walnut Street and intersects Pennsylvania Route 248 which leads to Pennsylvania Route 987 and Pennsylvania Route 329. North of Bath in Moore Township, PA 512 becomes Moorestown Drive. In the village of Moorestown, PA, PA 512 intersects Pennsylvania Route 946. In Bushkill Township, PA 512 becomes Moorestown Road. In Plainfield Township, PA 512 intersects Pennsylvania Route 33. As PA 512 enters Wind Gap it is called Broadway and meets Sullivan Trail (formerly Pennsylvania Route 115). Broadway continues as the former PA 115 while PA 512 turns to the east as Park Avenue and then Lehigh Avenue. PA 512 reenters Plainfield Township and is called Pennsylvania Avenue and passes by Waste Management Industries. As Pennsylvania Avenue, PA 512 enters Pen Argyl and later becomes Main Street and Blue Valley Drive. In Washington Township west of Bangor, PA 512 continues as Blue Valley Drive. In Bangor, PA 512 is called Market Street and intersects Pennsylvania Route 191. East of PA 191, PA 512 becomes Main Street and Erdman Street. PA 512 briefly reenters Washington Township and is called Central Avenue. In East Bangor, PA 512 remains Central Avenue and turns to the east. Outside of East Bangor, PA 512 enters Upper Mount Bethel Township and becomes Mount Bethel Highway and parallels railroad tracks. In Upper Mount Bethel Township, PA 512 terminates at a "T" intersection with Pennsylvania Route 611.

Pennsylvania Route 512 has gone through many designations since its addition in 1928. They were the following:

In the 1970s, the northern terminus was moved from PA 115 in Wind Gap to PA 611 in Mount Bethel.

The entire route is in Northampton County.