The National Championship was the next stage from the regional stage of
2020–21 Thai League 3
The 2020–21 Thai League 3 is the fourth 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 Omsin League Regional Championship due to the spons ...
. The winners and runners-ups of each region would qualified to this round to finding three clubs promoting to the
2021–22 Thai League 2
The 2021–22 Thai League 2 is the 24th 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 ...
.
Teams
Note:
Qualifying play-offs
Play-off round
, -
!colspan=3, Northern region
, -
!colspan=3, Bangkok metropolitan region
:Northern region
:Bangkok metropolitan region
Group stage
Upper region
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Lower region
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Knockout stage
Winners, runners-up, and third place of
2020–21 Thai League 3
The 2020–21 Thai League 3 is the fourth 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 Omsin League Regional Championship due to the spons ...
would be promoted to the
2021–22 Thai League 2
The 2021–22 Thai League 2 is the 24th 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 ...
.
Third place play-off
Summary
Matches
''Rajpracha won 2–1 on aggregate.''
Final
Summary
Matches
=1st leg
=
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=2nd leg
=
''Lamphun Warriors won 3–2 on aggregate.''
Statistics
Goalscorers
Teams promoted to 2021–22 Thai League 2
:* Lamphun Warriors (champions)
:* Muangkan United (runners-up)
:* Rajpracha (third-placed)
References
{{DEFAULTSORT:2020-21 Thai League 3 National Championship
Thai League 3
3