Students and staff of Overton Grange School in Stanley Road were evacuated at 3.30pm today (December 13).
Officers conducted a search of the premises and the incident was stood down shortly after as nothing was found.
Your Local Guardian has contacted Overton Grange School for a further information on the incident.
A spokesperson for Metropolitan Police said: “Police were called at 15:30hrs on 13 December after a school in Stanley Road, Sutton, received a threatening phone call.
“The school decided to evacuate and police and staff conducted a search of the premises.
“Nothing was found and the incident was stood down.”