The incident happened in St Nicholas Way just after 11.15am yesterday (June 26).
Officers and London Ambulance Service crews attended and found a man injured.
He was taken to hospital for treatment where his condition was assessed as non-life threatening.
No arrests have been made as police enquiries continue.
A spokesperson for Metropolitan Police said: “On Thursday, 26 June at 11:16hrs police were called to reports of a road traffic collision between a bus and a pedestrian at St Nicholas Way, Sutton.
“Officers attended the scene alongside the London Ambulance Service who treated the pedestrian, a 64-year-old man, before transporting him to hospital.
“His injuries are not believed to be life-changing or life-threatening. There have been no arrests at this stage.”
A spokesperson for London Ambulance Service said: “We were called at 11.17am today (26 June) to reports of a road traffic collision on St Nicholas Way, Sutton. We sent an ambulance crew and a paramedic in a fast response car to the scene.
“We treated a man at the scene and took him to a local hospital.”
