It happened on the 1300 block of South 49th Street around 6:45 p.m. in the city's Kingsessing section.
According to Chief Inspector Scott Small, video obtained by police shows the teen involved in an altercation with a group of other males, possibly juveniles, before the victim gets shot one time in the arm.
The boy was transported to Children's Hospital of Philadelphia where he's currently listed in stable condition.
"As far as we know the bullet hit him in the arm and broke his upper arm... Based on ballistic evidence, we know at least one shot was fired from a semi-automatic weapon. We found one spent shell casing on the sidewalk," said Small.
No arrests have been made.
Anyone with any information is asked to call police at 215-686-TIPS.