Map - Noi Bai International Airport (Noi Bai International Airport)

Nội Bài International Airport (Sân bay quốc tế Nội Bài) in Hanoi, the capital of Vietnam, is the second largest and busiest airport for passenger traffic, after Tan Son Nhat International Airport. It is currently the main airport serving Hanoi, replacing the role of Gia Lam Airport. The airport consists of two passenger terminals. Terminal 1 serves domestic flights, and the newly built Terminal 2 (inaugurated on 4 January 2015) serves all international flights to and from Hanoi. The airport is currently the main hub of the flag carrier Vietnam Airlines, travel carrier Vietravel Airlines, and budget carriers Bamboo Airways, Pacific Airlines and Vietjet Air.

The airport is located in Phu Minh Commune in Sóc Sơn District, about 35 kilometres (21 miles) northeast of downtown Hanoi, via the new Nhật Tân Bridge (also inaugurated on 4 January 2015). It can also be reached by National Road 3, which connects it with the eastern suburbs of Hanoi. The airport is also close to some satellite cities of Hanoi such as Vĩnh Yên, Bắc Ninh and Thái Nguyên. The airport served a total of 13 million passengers in 2013, despite having a capacity of only 9 million at the time. The new international terminal, which had its first commercial flight on 25 December 2014 and went into full operation on 31 December 2014, has boosted the airport's total capacity to 20 million passengers per year. In 2018, the airport served 28 million passengers. The airport's IATA code, HAN, is derived from the city's current name of Hanoi.

Of the routes the airport offers, the Hanoi – Ho Chi Minh City route is the busiest in Southeast Asia and the sixth busiest in the world, serving 6,867,114 customers in 2018.

The airport was developed immediately south of the Phúc Yên Air Base and opened on 2 January 1978. The terminal 1 building was completed and became operational in 2001.

In 2005, Tiger Airways started thrice-weekly flights between Hanoi and Singapore after launching direct flights between Hồ Chí Minh City and Singapore becoming the first budget airline to operate in Vietnam. It was later joined by low-cost carrier AirAsia when they launched direct flights between Hanoi and Bangkok and Kuala Lumpur.

The second runway (1B – 11R/29L) opened in 2006 and the following year the airport hosted an Airbus A380 for the first time, although no scheduled A380 services are operated from the airport. 2013 saw the first arrival of a Cargolux Boeing 747-8F. In 2014 the airport received its first scheduled service with the newest generation of commercial aircraft when All Nippon Airways started using a Boeing 787-8 on services between to Tokyo–Haneda and later the same year the airport received its first visit of Airbus A350 XWB operated by Airbus on World Tour trip. In 2015, Vietnam Airlines started to operate the Airbus A350 XWB for commercial domestic flights.

The airport has been a SkyTeam hub since mid-2010, after Vietnam Airlines joined the network that year.