The incident happened in Erith Road near Brook Street just before 3pm today (January 22).
Officers and London Ambulance Service crews attended and found the pedestrian injured.
They were taken to hospital for treatment where their condition was assessed as serious.
Erith Road remains closed between Rutland Gate and Brook Street as the incident is being dealt with.
A spokesperson for Metropolitan Police said: “Officers are currently on the scene of a collision on Erith Road, Belvedere.
“Police were called at 14:58hrs on Wednesday, 22 January following reports of a collision involving a car and a pedestrian.
“The pedestrian has been taken to hospital with serious injuries.
“Emergency services remain on scene and the road remains closed.”
