The victim in his twenties was found suffering from gunshot wounds inside a house in Baynes Close in the early hours of Saturday.
Police and paramedics rushed to the scene at 12.50am.
A statement from the Metropolitan Police said: “A man in his 20s was found inside the address with a gunshot injury.
“The London Ambulance Service (LAS) attended and the man was treated by paramedics before being taken to hospital.
“He remains there in a critical condition.”
The shooting came just hours after another man was shot and stabbed to death in nearby Wood Green.
A man, 19, was killed after a fight in Vincent Road which police were called to around 8pm on Friday.
Officers raced to Vincent Road in Wood Green, Haringey, at about 8pm on Friday night following reports of a group fighting.
There police found two men – believed to be aged 19 and 20 – with knife and gunshot injuries.
No arrests have been made.
Enquiries continue by officers from the Trident and Area Crime Command.
Anyone with information is asked to contact police on 101 or tweet @MetCC quoting ref: CAD335/23Feb.
Alternatively, call Crimestoppers anonymously on 0800 555 111.