The suspected hit-and-run happened early on Saturday morning, and police are searching for the car and driver involved.
She was struck by a car "travelling at speed" in the early hours of Saturday morning, and was pronounced dead at the scene.
Detectives believe a dark-coloured VW - possibly a Golf - was involved.
Police were called to the junction of Brixton Hill and Dumbarton Road at about 12.30am.
The force said: "The driver of the vehicle, which was travelling at speed, did not stop at the scene and enquiries are under way to trace it."
A spokesman added that the car involved "may have sustained damage to the bonnet" as a result of the incident.
:: Any witnesses or people with information that could assist investigators were asked to call 101 ref CAD 183/12 Jan.