Police officers on patrol saw the crash on the East India Dock Road in Poplar around 1.45pm on August 20.
The man was taken to hospital by the London Ambulance Service in a life-threatening condition.
He later died in the hospital.
The driver of the car stopped at the scene and no arrests have been made.
Pensioner fighting for his life after being hit by car on A13
Officers are appealing for information from members of the public as enquiries continue.
A Met Police spokesperson said: “While on patrol, Met officers witnessed a road traffic collision involving a car and a pedestrian in East India Dock Road at 13:42hrs on Wednesday, 20 August.
“The pedestrian, a 77-year-old man, was treated at the scene by paramedics from the London Ambulance Service and was later taken to hospital.
“Sadly, despite their best efforts, he later died at hospital.
“The driver of the car involved in the collision stopped at the scene. No arrests have been made.
“Officers are interested in hearing from those with information – particularly anyone with dashcam footage from the scene at the time of the incident.
“Please report this to the Met by calling 101, quoting 3945/20AUG.
“Enquiries continue.”
