Pennsylvania Route 56 (PA 56) is a major 108-mile (174 km) long state highway located in central Pennsylvania. Its western terminus is at the eastern approach to the C.L. Schmitt Bridge in New Kensington. Its eastern terminus is U.S. Route 30 west of Bedford.

PA 56 starts at an intersection with PA 366 in Arnold. It then heads east into Westmoreland County. While in Westmoreland County, it merges with PA 66. It then travels east and eventually merges with PA 156, crossing into Indiana County. At this point, it merges with U.S. Route 422 and heads toward Indiana. In Indiana, U.S. Route 422 and PA 56 become a short freeway. At the U.S. 119 exit, PA 56 merges with U.S. Route 119, heading south. PA 56 breaks away from U.S. 119 outside of Indiana and continues east on a two-lane road. Approaching Armagh, it crosses U.S. Route 22 at an interchange. The route then enters Westmoreland County again briefly, passing through its extreme northeastern corner. It is at this point, that PA 56 crosses through Seward. A short time after passing through Seward, it crosses into Cambria County. Continuing east, it travels along the southern side of the Conemaugh River through the Conemaugh Gap. It then emerges into the city of Johnstown. PA 56 travels through the heart of the West End section of Johnstown on two-lane city streets. With the countless trucks traveling through the West End, a PA 56 bypass has been discussed for quite some time. However, very little progress on the topic has been made, and it is yet to be seen if it will ever become a reality. It then merges with PA Route 403 on Broad Street, a four-lane road containing many traffic signals. At the final signal, it breaks away from Route 403 and becomes a freeway entitled Johnstown Expressway. This expressway is actually a bypass constructed in the mid-1960s. The original route continued on city streets and crossed under U.S. Route 219 in Richland Township. Currently, PA 56 enters the four-lane expressway and meets U.S. Route 219 a short distance north from its original connection. It eventually exits U.S. 219 at Scalp Avenue, the original interchange, and continues east toward Windber. The Route enters Somerset County at Windber. Once past Windber, PA 56 returns to two-lanes. It enters Bedford County at the top of Laurel Ridge at 2700 feet above sea level. The descent down the eastern slope contains a dangerous hairpin curve that has been the site of many accidents over the years. It then crosses Interstate 99 / U.S. Route 220 at an interchange near Cessna. After a short distance, PA 56 crosses over Interstate 99 / U.S. Route 220, then later passes under the Pennsylvania Turnpike. The route ends at a "T" intersection with U.S. Route 30 in Wolfsburg, west of Bedford and east of the Little Barn Discount Grocery.

Pennsylvania Route 56 Truck is a 2-mile (3.2 km) long truck route in the Pittsburgh industrial suburb of New Kensington, Pennsylvania. The route's western terminus also marks the end of its parent, as each formulate a different way of travel for those who have crossed the C.L. Schmitt Bridge. While Route 56 makes several turns as it passes through the stop light-filled center of the community, the truck route runs as the four-lane Industrial Boulevard along the Allegheny River, before turning back north as it is multiplexed with Pennsylvania Route 366.