Team members participating in seven disciplines – badminton, shooting, skeet shooting, cycling, boxing, swimming and table tennis -- left for the Games from July 23 to August 8.
Among the departing athletes was badminton star Ratchanok Intanon, who will carry the Thai flag during the opening ceremony.
Ratchanok, ranked sixth in the world in singles, said she had trained as much as possible, after being unable to visit a court for 3-4 months.
The Games will be held without spectators to prevent the spread of Covid-19.
Athletes from 205 nations will compete in 33 different sports. Thai athletes have qualified to compete in 16 disciplines.