The incident happened on Norwood High Street near a junction with Gipsy Road and Chapel Road around 5pm yesterday (January 30).
Officers and London Ambulance Service crews attended and found 10 people injured.
They were all treated at the scene and six of them were taken to hospital for further treatment.
Norwood High Street was partially blocked in both directions and the 432 towards Anerley was diverted.
However, all closures have since been lifted.
A Metropolitan Police spokesperson said: “Police were called by the London Ambulance Service at 17:09hrs on Thursday, 30 January to reports of a collision involving a car and a bus on Norwood High Street.
“Officers attended. A number of people were treated at the scene.”
A London Ambulance Service spokesperson said: “We were called at 5.03pm today (30 January) to reports of a road traffic collision in Norwood High Street.
“We sent a number of resources to the scene including ambulance crews, an advanced paramedic and incident response officers.
“We treated 10 patients and took six of them to hospital.”
