Thailand will host 12,506 athletes at the 33rd Southeast Asian Games, which will take place in Bangkok, Chon Buri and Songkhla later this year.
Thailand will be the country with the most representatives, with 1,807 athletes participating in the Dec 9-20 tournament.
Malaysia will have the second largest contingent with 1,580 athletes while Indonesia will send 1,548 athletes to Thailand 2025.
Cambodia, who is currently engaged in border dispute with Thailand, will be the fourth largest contingent with 1,515 athletes.
Other countries include Brunei (250), Laos (598), Myanmar (1,077), the Philippines (1,499), Singapore (1,481), Timor Leste (132) and Vietnam (1,019).
A total of 6,253 officials from 11 countries will participate in the tournament.
The deadline for entry forms by name is Sept 1 and the draw for team sports will take place on Oct 18-19.
It is the seventh time Thailand will be hosting the biennial Games, having previously done so in 1959, 1967, 1975, 1985, 1995 and 2007.