Officers were called just before midnight on Saturday, July 11 by ambulance workers after the teen was knifed in the chest outside the Mossy Well pub in Muswell Hill Place.
The boy had been involved in an "altercation" with a group of men, police said, after which he was knifed.
The victim was rushed to hospital. His injuries were not considered life-changing and he was later sent home.
No arrests have been made so far. Officers have now released CCTV footage and images of the four men they want to speak to in connection with the attack.
Detective Constable James Green, investigating, said: “The victim became involved in an altercation with a group of males near the Mossy Well pub in Muswell Hill when he was set about and attacked.
“But for the speed and skill of emergency services workers, this incident could have had a very different outcome.
"I am urging any members of the public who recognise any of these males to make contact with us immediately.”
Officers are encouraging anyone who has any information regarding the attack to call them on 101 quoting reference 9656/11Jul. Alternatively tweet @MetCC or contact Crimestoppers anonymously on 0800 555 111.