Under the plan recently approved by the transport ministry, the airport in Ho Chi Minh City will be around eight hectares bigger.
The expansion will allow 82 airplanes to be parked at the same time, twice the current number.
With the exception of runways, many parts of the airport including its terminals will also be upgraded so that it can serve 25 million passengers a year in 2020.
Tan Son Nhat Airport received more than 22 million passengers last year, compared to its designed capacity of 20 million passengers, Deputy Transport Minister Nguyen Nhat said.
The capacity of its goods terminal which handled 406,000 tons last year will also be increased to 500,000 tons a year.
However, Nhat warned, even after expansion, congestion will likely continue at the airport as Long Thanh, a bigger airport designated to replace Tan Son Nhat, will not be operational until 2023.
The number of passengers at Tan Son Nhat has been projected to hit 40 million a year by 2025.
Located in the nearby Dong Nai Province, about 40 kilometers from the city, Long Thanh Airport is slated to serve 100 million passengers and 5 million tons of goods annually.
Construction of the first stage will start in 2019, expected to cost US$15.8 billion.