There would be four weekly flights on Mondays, Wednesdays, Fridays, and Sundays, the airline said on its website.
The Bangkok-Da Lat route was launched in 2017 and suspended in March 2020 as Vietnam closed its borders due to the pandemic.
Woranate Laprabang, general director of Thai Vietjet, said the resumption of the service would be a boost to economic and tourism recovery with both Thailand and Vietnam lifting most Covid travel restrictions.
Thailand has sent the fourth highest number of visitors to Vietnam this year - 153,400 - while Vietnam is one of That country’s largest source of foreign visitors post reopening with over 373,000, according to official statistics.
Situated on a plateau in the Central Highlands at around 1,500 meters above sea level, Da Lat enjoys year-round cool weather and is famous for its French colonial heritage.