SEPTA's subway–surface trolley route 34, also called the Baltimore Avenue subway line, is a trolley line operated by the Southeastern Pennsylvania Transportation Authority (SEPTA) that connects the 13th Street station in downtown Philadelphia, Pennsylvania, to the Angora Loop station in the Angora neighborhood of West Philadelphia.

[3] At 10.1 miles (16.3 km), it is the shortest of SEPTA's five subway–surface trolley lines, which operate on street-level tracks in West Philadelphia and Delaware County, Pennsylvania, and in a shared subway with rapid transit trains in Center City.

From 15th to 30th Streets, it runs on the outer tracks in the same tunnel as SEPTA's Market–Frankford Line.

The Delaware County and Philadelphia Electric Railway Company installed transit tracks for horsecars running along Baltimore Avenue as early as 1890, but it was the arrival of the electrified trolley two years later that allowed the extension of the line westward to the new community of Angora.

[4] In April 2020, the line's operations were suspended due to the COVID-19 pandemic.