The green light has been given to the north-south cycle superhighway which will link Elephant and Castle with King’s Cross.
Work will begin in the spring and the route will run for 5km on roads either fully separated from traffic or on "quiet back streets".
It will be known as Cycle Superhighway 6 once complete and will "provide a safe and direct route for cyclists".
The announcement by the Mayor of London Sadiq Khan and Transport for London comes on the same day Team GB's medal winning Olympic cyclists called for "a legacy of everyday cycling" to be created, instead of being given honours.
The letter to Prime Minister Theresa May, which includes the name of Harlow’s four-time Olympic champion Laura Trott, urges her to devote 5% of the government’s transport spend to cycling infrastructure.