The incident is believed to have taken place on Belinda Road, SW9 shortly after 06:00hrs.
The man was admitted to a south London hospital to be treated for the gunshot injuries, where he later died.
No arrests for the shooting have yet been made and the police have been continuing their enquiries.
A statement from the Metropolitan Police reads: “At around 06:25hrs on Thursday, 21 October, police were alerted by staff at a south London hospital after a man in his 20s was admitted suffering gunshot injuries.
“Despite the efforts of emergency services, he died later this afternoon.
“It is believed the man sustained his injuries following a shooting in the vicinity of Belinda Road, SW9 shortly after 06:00hrs.
“A crime scene remains in place.
“No arrests have been made and enquiries into the circumstances continue.
“Additional officers will be patrolling in and around the area and anyone with concerns is asked to speak to them.
More to follow