Buriram United are the defending champions, while Lamphun Warriors, Sukhothai and play-off winner Lampang have entered as the promoted teams from the 2021–22 Thai League 2.

Samut Prakan City, Suphanburi and Chiangmai United were relegated at the end of the 2021–22 season after finishing in the bottom three places of the table.

Chiangmai United made their immediate return to the second-tier, while Suphanburi ended a 9-year stint in the top-flight.

The three were replaced by 2021-22 Thai League 2 champions Lamphun Warriors, who are making their maiden appearance in the top flight.

They were joined by runners-up Sukhothai, who made their immediate return to the top flight and Lampang, the promotion playoff winner which was first held in 2020–21 season.