The Ninth Street Branch was an elevated railway line in Philadelphia, Pennsylvania. It was operated by the Reading Company; ownership was split between the Reading and its subsidiary the Philadelphia, Germantown and Norristown Railroad. It was a four-tracked main line beginning at the Reading Terminal, the Reading's terminus in Philadelphia, and extending north into the city to a junction with the Bethlehem Branch. After the final bankruptcy of the Reading the line passed to Conrail and later SEPTA. The portion south of the Temple University station was abandoned in 1984 with the opening of the Center City Commuter Connection and is now known as the Reading Viaduct; the portion north is now part of the SEPTA Main Line.

The SEPTA Main Line is the section of the SEPTA Regional Rail system from the Zoo Interlocking in West Philadelphia to Lansdale Station in Lansdale, Pennsylvania. The line is 26.25 miles (42.25 km) long, and serves all 13 SEPTA Regional Rail lines.