The incident happened at 12:35 a.m. Tuesday in the 4800 block of North Broad Street in the Logan section.
Investigators say three men followed the victim, a 25-year-old man, onto the bus.
The video then shows the suspects punching and kicking the victim in the back of the bus.
The victim suffered injuries to the eye, face and arm.
The three men then ran away at another bus stop.
The suspects are described by police as:
Suspect #1: Black male, late teens to early 20s, with a goatee, medium build, wearing a white t-shirt, Khaki style pants, black/blue and white New Balance sneakers.
Suspect #2: Black male, late teens to early 20s, wearing a white tank top, dark shorts and white/black Puma sneakers.
Suspect #3: Black male, late teens to early 20s, stocky build, wearing a yellow with blue stripes Polo shirt, dark jeans and white sneakers.
Anyone with information is asked to contact Philadelphia Police at 215-686-TIPS (8477), text a tip to PPD TIP (773847) or go to PhillyPolice.com.