Police were called at just after 9pm on Wednesday, 7 December to reports of a stabbing on Longbridge Road at the junction with Sandhurst Drive in Ilford.
Officers rendered first aid to the male who has been stabbed a number of times.
Paramedics and Doctors from the London air ambulance were also called to the incident. Medical equipment can be seen at the front of the bus.
The man has been rushed to the major trauma unit at the Royal London.
A large crime scene remains in place with a number of London buses stuck within the Police crime scene.
Due to the Road being blocked in both directions at the junction with Sandhurst Drive a number of bus routes have been affected: 5,145,EL2,EL3,N15 these are running a revised route.
The Met Police and London Ambulance service have both been approached for statements.