It happened just after 6:00 p.m. near the North Hills Station at Station and Mt. Carmel Avenues in Glenside.
Police say the 20-year-old Ardsley man entered the track area and tried to cross the fence separating the east and westbound tracks at the station, but was unable to make it back to the platform in time.
He was struck by a SEPTA express commuter train on the Lansdale-Doylestown line. He was pronounced dead at the scene.
Service was suspended for more than two hours during the investigation.
The victim's identity has not been released.
The accident remains under investigation.