The incident happened just after 4:30 p.m. at the 34th Street Station on Market Street.
Police say a male stabbing victim was located on the subway platform.
He was transported to Penn Presbyterian Medical Center for stab wounds to the chest and hand.
According to a SEPTA spokesperson, the injuries were non-life-threatening.
A suspect was taken into custody, police say.
The suspect's identity has not been released at this time.