Nội Bài International Airport (IATA: HAN, ICAO: VVNB) (Vietnamese: 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.