The project was approved last year.
The plant, located in Quang Tri province, will have a power generation capacity of 1.5 GW and run on regasified LNG.
The LNG will be imported via a 1.5 million metric tons/year receiving and regas terminal.
The plant is expected to be ready by 2026-27.
Vietnam's T&T group and South Korea's Korea Southern Power Corp (Kospo), Hanwha Energy Corp and Korea Gas Corp (Kogas) are the project's developers, the government said.
T&T group will contribute 40% of the investment capital and while Hanwha, Kospo, Kogas will together contribute 60%.
The southeast Asian nation is promoting gas-fired power as it moves away from coal and oil-based generation.
It aims to cut GHG emissions by 27% in 2030 (with international support).