The Pittsburgh Line is a rail line owned and operated by the Norfolk Southern Railway in the U.S. state of Pennsylvania. The line spans 248 miles (399 km) between its namesake city of Pittsburgh in the western part of the state and Harrisburg in the central region. It forms part of the longer Keystone Corridor, which continues east to Philadelphia via Amtrak's Philadelphia to Harrisburg Main Line.

The Pittsburgh Line is Norfolk Southern's primary east–west artery through its Pittsburgh and Harrisburg divisions. Along its route, the line crosses the Allegheny Mountains via the Gallitzin Tunnels west of Altoona and the Horseshoe Curve. At its eastern end, it connects with the Harrisburg Line, providing access to Reading and Philadelphia. At its western end, it connects with the Fort Wayne Line toward Conway, Pennsylvania, linking to points west in Ohio and Indiana.

The line is one of Norfolk Southern's busiest freight corridors, with approximately 50 to 70 trains daily, and serves as a major route for intermodal traffic between the Northeast and the rail hubs in Chicago.^{[citation needed]}

The Pittsburgh Line was originally owned by the Pennsylvania Railroad (PRR). It began as two rail lines, the Middle Division Main Line which was part of the PRR Middle Division and the Pittsburgh Division Main Line which was part of the PRR Pittsburgh Division. The Pennsylvania Railroad combined the Middle Division Main Line and the Pittsburgh Division Main Line into one rail line, forming the Pittsburgh Line, though at the time the Pittsburgh Line was not referred to by that name. At the same time the Middle Division and the Pittsburgh Division were also combined.

The Pennsylvania Railroad eventually combined the merged Middle Division/Pittsburgh Division Main Line with their main rail line to Philadelphia, forming the Main Line of the Pennsylvania Railroad (now known as the Keystone Corridor). The Main Line served as the PRR's primary route across Pennsylvania, continuing its existence through the Penn Central years and the early years of Conrail.

Conrail broke the PRR Main Line into two rail lines again, reestablishing the Pittsburgh Line and the PRR Philadelphia main line which eventually became known as the Philadelphia to Harrisburg Main Line, now under the ownership of Amtrak. The Pittsburgh Line received its current name in the 1980s under Conrail.

The Pittsburgh Line was passed down to the Norfolk Southern Railway in 1999 during the breakup of Conrail between Norfolk Southern and CSX Transportation.

The Pittsburgh Line is marked with three major freight terminals at its ends. On its east end, Harrisburg Terminal handles the bulk of the railroad's intermodal traffic, with a handful of intermodal trains originating and terminating there. Across the Susquehanna River in Enola is Norfolk Southern's major freight terminal in the Greater Harrisburg area: Enola Yard, which handles almost all manifest freight traffic that passes through the area. Many of the Pittsburgh Line's manifest freight trains originate or terminate here, with a few continuing south to Baltimore and points east, while others bypass Enola and cross the Rockville Bridge over the Susquehanna to Harrisburg bound for Allentown and points east.