Andre Shenz, named locally by friends and relatives, was stabbed several times outside a low rise block of flats in Selsdon, South Croydon, at around 7.40pm tuesday.
Despite the efforts of paramedics and an air ambulance crew he died in hospital.
Two 19-year-olds have been arrested in connection with his murder and are currently being quizzed at separate police stations in south London.
Mr Shenz's death comes just 24 hours after the murder of 18-year-old Lance Scott Walker, who was knifed to death after 'running for his life' down a suburban street in Hayes, west London.
Earlier this year the Met said it was called to more than 9,000 knife crime incidents in London in the year ending April 2016.
The teenager collapsed in the street and the attacker is said to have sat beside him and repeatedly stabbed him in the back as children looked on during the incident on Monday night.
Idris Hassan, 18, who lived on the estate and is believed to have known the victim, has been arrested and charged with murder in connection with Mr Walker's death.
Mr Shenz has become the eighth teenager to have been murdered in London this year - four of the killings occurred in August alone. All were victims of knife crime.
Mr Shenz's death has also been linked to the murders of two other young rappers who have been killed on the streets of the capital in the last four months. All three were said to be friends.
The teenager, of Thornton Heath, south London, is pictured on Facebook in an embrace with 17-year-old Myron Isaac Yarde, who was fatally stabbed in Battersea, south London, on April 3.
Myron was an aspiring rapper who performed under the name of Mdot.
His friend 16-year-old Leoandro Osemeke, also an up-an-coming rapper, was stabbed to death at a barbecue party near his home in Peckham, south east London, on August 5.