Police were called just before 7 p.m. Tuesday to the 5200 block of Pentridge Street in the city's Kingsessing section.
Arriving officers found a 15-year-old boy suffering from multiple gunshot wounds to his chest and arm.
He was rushed to the hospital where he later died.
The boy has been identified as Antonio Walker Jr.
"We're getting information that this 15-year-old was walking south on 52nd Street with at least one other juvenile when a car pulled up northbound and the shooter exited the car and began firing shots at that 15-year-old and the person he was with," Philadelphia Police Chief Inspector Scott Small said.
Police are trying to figure out if the 15-year-old was the intended target or not.
Detectives are hoping cameras in the area will help catch those involved.
This marked the city's 90th homicide in 2021.
Another 15-year-old was shot in the leg just before 3 a.m. Wednesday at Frankford Avenue and Chippendale Street in Mayfair, police said.
The victim told police he was shot outside a minimarket.
Police say the shooting stemmed from an argument involving two other men in the market.
He was taken to the hospital in stable condition.
Police are still searching for the shooters.
Anyone with any information is asked to call police at 215-686-TIPS.