The Metropolitan Police were called to Stoke Newington School on Clissold Road at 11.55am on Thursday.
Officers remain at the scene and a cordon is in place while they investigate, a police statement said.
Footage from the scene shows police vehicles outside the school and students and staff leaving the premises.
The Metropolitan Police tweeted: “At 11:55hrs on Thursday, 10 December, police were contacted by staff at a school in Clissold Road, Stoke Newington #Hackney.
“The school had received a bomb threat. The school was evacuated and officers are in attendance.”
The school is understood to be shutting early today while police complete checks of the building.
Hackney Council said that Clissold Road and Clissold Leisure Centre are also closed, and advised people to avoid the area.
A spokesperson for the council said: “Stoke Newington School is closing early today following an incident. Staff and students have been evacuated, and the police are completing checks of the building.
“Clissold Road and Clissold Leisure Centre are also closed. Please avoid the area while the closure is in place.”