It happened around 7 p.m. on the 1500 block of Chestnut Street.
Police say they found the victim suffering from a stab wound to the back in the entrance to Liberty Place at 16th and Chestnut.
The victim was transported to an area hospital for non-life threatening injuries.
No arrests have been made. Police say they are looking for a man and woman in connection with the stabbing.
Anyone with any information is asked to call police at 215-686-TIPS.