Rickarlo Williams 18 of no fixed address, and Jahni Menzie-Samuels 18 of no fixed address, have also been charged with two counts of attempted murder and possession of an offensive weapon.
They are both due to appear at Willesden Magistrates’ Court on Monday, 21 December.
A murder investigation was launched after Hussain Al Saabri was found with fatal stab injuries in St Anns Road, Harrow, at 7.15pm on Sunday, 13 December.
Two further males – aged 17 and 19 years – also suffered stab injuries. Their injuries are not life-threatening.
A post mortem on 15 December established Hussain’s cause of death as stab wound to the abdomen.