The 29-year-old was arrested on the afternoon of Thursday, 8 July. He remains in custody at a south London police station.
Police were called at approximately 23:45hrs on Monday, 5 July, to a teenager stabbed in Oval Place, SW8.
Officers attended along with London Ambulance Service. The 16-year-old male was pronounced dead at the scene.
He has since been named as Keane Flynn-Harling. His family are being supported by specially trained officers.
Detectives from the Met’s Specialist Crime Command are leading the investigation and continue to appeal for witnesses.
Anyone with information is asked to call police on 101 or tweet @MetCC quoting CAD 8532/05Jul. To remain 100% anonymous, call Crimestoppers on 0800 555 111.