The 26-year-old fell from a building on International Way, Stratford. Metropolitan Police officers were called to the area just after 4.30pm on Tuesday to reports of an offence.
A man was arrested and taken to custody.
Just before 5.45pm, a woman fell from a block of flats.
Officers called to the scene provided first aid.
London Ambulance Service and an air ambulance also attended.
The woman died a short time after the fall.
Police said her next of kin have been informed and an investigation is underway.
The Met Police said in a statement: "A 26-year-old woman has died after a fall from height from a block of flats in International Way, Stratford.
"Police were called to the location shortly after 16.30hrs on Tuesday, August 17 to a report of an offence.
"Officers attended and a man was arrested. He has been taken into custody.
"Shortly before 5.40pm, it was reported that a woman had fallen from height.