The crash happened just before 2 p.m. at the intersection of S. Henderson Road and Monroe Road.
Video from Chopper 6 showed a car with front-end damage, an SUV with damage to its front and side, and the SEPTA bus stopped at the scene.
SEPTA said the Route 99 bus was involved.
Chopper 6 over scene of multi-vehicle crash in King of Prussia
Injuries were reported in this crash, but the severity of those injuries was not immediately known.
The cause of the crash is under investigation.