About Hanoi Hanoi is the capital of the Socialist Republic of Vietnam and the second-largest Vietnamese city after Ho Chi Minh City ( Saigon ). It has an estimated population of 7.7 million as of 2018, and with the metropolitan area included arises to 16 million. Located in the central area of the Red River Delta, Hanoi is the commercial, cultural, and educational center of Northern Vietnam. The capital of Vietnam is one of the most ancient capitals in the world with over 100