The 2020–21 Thai League 2 is the 23nd season of the Thai League 2, the second-tier professional league for Thailand's association football clubs, since its establishment in 1997, also known as M-150 Championship due to the sponsorship deal with M-150. A total of 18 teams will compete in the league. The season began on 14 February 2020 and is scheduled to conclude on 31 March 2021. For this season two teams in the final table (champion and runner up) directly promoted to Thai League 1 next season while teams ranked 3rd - 6th qualified in play off for last spot in top tier next season.