Buriram United are the defending champions, while Nakhon Ratchasima, Nongbua Pitchaya, and Rayong have entered as the promoted teams from the 2023–24 Thai League 2.
Chonburi, Police Tero and Trat were relegated at the end of the 2023–24 season after finishing in the bottom three places of the table.
The three were replaced by 2023-24 Thai League 2 champions Nakhon Ratchasima F.C., who are returning to the top-flight after a single year away.
Note: Flags indicate national team as has been defined under FIFA eligibility rules.
Each team can register a maximum of nine foreign players, including a slot from the AFC and no more than three from the AFF.