The Airports Corporation of Vietnam (ACV) would be the developer and fund the construction, city authorities said in a statement.
The 64,000-square-meter terminal will be able to handle 100,000 tons of goods a year.
Construction is set to begin in the first quarter of 2022.
Hai Phong, two hours east of Hanoi by road, is home to a key port for both domestic and international trade.
The city administration wants to build an airport in Tien Lang District to reduce the overload on Hanoi's Noi Bai International Airport.