40th Street station is an underground station on the SEPTA Market-Frankford Line, located the intersection of 40th Street and Market Street in Philadelphia, Pennsylvania, on the line between the Spruce Hill and Powelton Village neighborhoods in the University City District of West Philadelphia. The station serves a major shopping corridor of West Philadelphia on 40th Street, as well as the campus of the University of Pennsylvania, which lies three blocks south of the station.

The station is served by SEPTA City Bus routes 30, 40 and LUCY. The station also serves as the inbound terminal for the SEPTA subway-surface trolley lines when services are diverted from the Market Street tunnels –– on Mondays from 12:00 a.m. to 5:00 a.m. and during any other unforeseen circumstances. All five trolley routes terminate at the intersection 40th Street and Market Street, just outside entrances to the Market–Frankford platforms.

40th Street station was opened on November 6, 1955 by the Philadelphia Transportation Company, built to replace the elevated station that opened in 1907 as part of Philadelphia Rapid Transit Company's (PRT) original Market Street subway–elevated line from 69th Street T.C. to 15th Street, which was elevated west of 23rd Street.

The PRT announced a project to bury the elevated tracks between 23rd to 46th streets in the 1920s. The tunnel from 23rd to 32nd streets was completed by 1933, but construction on the remaining segment was put on hiatus due to the Great Depression and World War II. The PRT went bankrupt in 1939 and was reorganized as the PTC, which began building the rest of the tunnel in 1947.

The station was renovated in 2017, making it accessible to people with disabilities. Two elevators were installed, one for each platform, each of the four entrance stairwells were covered with artistic screens, and underground lighting and tiles were replaced. The project was completed on October 21, 2017, at a total cost of $10.9 million.

The station has two side platforms with separate fare control on either side. West of the station, the tracks climb out of a portal near 44th Street and run west as an elevated line.

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  New stairwell tile installed in 2017
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  Newly-designed station entrance built in 2017
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  Underground platform
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  Old 40th Street station signage from 2007
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  Diverted trolley at surface level

Media related to 40th Street (SEPTA Market–Frankford Line station) at Wikimedia Commons

• SEPTA – 40th Street station
• 40th Street entrance from Google Maps Street View