Police were called to Station Road, Wood Green, at about 03:20 BST after receiving reports of a stabbing outside the Jolly Anglers public house.
Paramedics treated the man, named by police as 33-year-old Vincent Harvey, but he was pronounced dead at the scene.
No arrests have been made and the Met have appealed for witnesses.
Det Ch Insp Noel McHugh said there was "a large number of people in and around the Jolly Anglers pub at the time Vincent was stabbed".
"It is vital that anyone who saw this incident, or the events leading up to the incident, get in contact with police," he said.
A murder investigation has been launched after a man was stabbed to death outside a busy north London pub.