2021–22 Thai League 3

The 2021–22 Thai League 3 is the fifth season of the Thai League 3, the third-tier professional league for association football clubs in Thailand, since its establishment in 2017, also known as Blue Dragon League due to the sponsorship deal with Blue Dragon Lottery Online. A total of 75 teams would be divided into 6 regions including 12 teams in the Northern region, 13 teams in the Northeastern region, 12 teams in the Eastern region, 11 teams in the Western region, 13 teams in the Southern region, and 14 teams in the Bangkok metropolitan region.

Regional stage
The number of teams in 6 regions including 12 teams in the Northern region, 13 teams in the Northeastern region, 12 teams in the Eastern region, 11 teams in the Western region, 13 teams in the Southern region, and 14 teams in the Bangkok metropolitan region.

Northern region

 * League table

Northeastern region

 * League table

Eastern region

 * League table

Western region

 * League table

Southern region

 * League table

Bangkok Metropolitan region

 * League table

National Championship stage
The national championship stage is the next stage from the regional stage. 1st and 2nd places of each zone qualified for this stage by being featured in 2 groups. Teams from the Northern, Northeastern, and Eastern regions would have qualified for the upper group. Meanwhile, teams from the Western, Southern, and Bangkok Metropolitan regions would have qualified for the lower group. Winners, runners-ups, and third-placed of the national championship stage would be promoted to the 2022–23 Thai League 2.

Group stage

 * Upper region


 * Lower region

Knockout stage

 * Third place play-off




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 * Final




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