The National Championship was the next stage from the regional stage of 2020–21 Thai League 3. 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.
Teams
TeamQualifying methodLamphun WarriorsNorthern region championsPhitsanulokNorthern region play-off winnerUdon UnitedNortheastern region championsMuang Loei UnitedNortheastern region runners-upPluakdaeng UnitedEastern region championsChachoengsao Hi-TekEastern region runners-upMuangkan UnitedWestern region championsRajprachaWestern region runners-upSongkhlaSouthern region championsKrabiSouthern region runners-upNorth Bangkok UniversityBangkok Metropolitan region championsBangkokBangkok Metropolitan region play-off winner
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
Lower region
Knockout stage Winners, runners-up, and third place of 2020–21 Thai League 3 would be promoted to the 2021–22 Thai League 2.
Third place play-off Summary
Matches
Rajpracha won 2–1 on aggregate.
Final Summary
Matches 1st leg
Lineups:GK 18 Adisak DuangsriCB 23 Witthawin KlorwuttiwatCB 70 Tana Sripandorn (c)CB 97 Torsak SaartaiamRM 33 Thanakorn Navanit CM 8 Akarapong PumwisatCM 22 Athit WisetsilpLM 15 Tongchai PonangRF 66 Anan Yodsangwal CF 37 João Paulo LF 14 Janepob Phokhi Substitutes:GK 36 Surasak Thong-aonDF 13 Siriphong AintaDF 55 Thanadol DumponngamMF 24 Adul NamwongMF 35 Siripong Kongjaopha MF 99 Nithikon ThaninchotirathFW 7 André Luís FW 20 Nutchanon KhaowsaardFW 26 Sarawut Sintupun Head Coach: Jongsarith Wuttichuay Lineups:GK 18 Suntiparp BoonlkilangRB 6 Chindanai WongprasertCB 15 Patipan Un-op CB 16 Koravit NamwisetLB 23 Rattasak Wiang-inDM 35 Saharat PanmarchyaDM 8 Suchao Nuchnum (c)RM 14 Montree Promsawat AM 38 Amorntep Nilnoy LM 13 Chakrit Rawanprakone CF 27 Bireme Diouf Substitutes:GK 1 Kantaphat ManpatiDF 4 Nattakrit ThongnoppakunDF 24 Jiranchai ArnanatiudomDF 48 Zady Moise GnenegbeMF 31 Anusorn PhrmprasitFW 10 Yuttana RuangsuksutFW 17 Patiphan Pinsermsootsri FW 19 Stéfano Yuri FW 33 Naphat Thamrongsupakorn Head Coach: Jadet Meelarp
2nd leg
Lineups:GK 18 Suntiparp BoonlkilangRB 6 Chindanai Wongprasert CB 48 Zady Moise Gnenegbe CB 16 Koravit NamwisetLB 23 Rattasak Wiang-in DM 35 Saharat Panmarchya DM 8 Suchao Nuchnum (c)RM 14 Montree Promsawat AM 38 Amorntep Nilnoy LM 13 Chakrit Rawanprakone CF 27 Bireme DioufSubstitutes:GK 1 Kantaphat ManpatiDF 4 Nattakrit Thongnoppakun DF 24 Jiranchai ArnanatiudomDF 99 Dantrai LongjumnongMF 31 Anusorn Phrmprasit FW 10 Yuttana Ruangsuksut FW 17 Patiphan Pinsermsootsri FW 19 Stéfano YuriFW 33 Naphat ThamrongsupakornHead Coach: Jadet Meelarp Lineups:GK 18 Adisak DuangsriRB 33 Thanakorn Navanit CB 23 Witthawin Klorwuttiwat CB 70 Tana Sripandorn (c)LB 97 Torsak SaartaiamRM 8 Akarapong PumwisatCM 35 Siripong Kongjaopha CM 22 Athit Wisetsilp LM 15 Tongchai PonangCF 37 João Paulo CF 7 André Luís Substitutes:GK 36 Surasak Thong-aonDF 55 Thanadol DumponngamMF 24 Adul NamwongMF 28 Kittisak BoonthaMF 99 Nithikon Thaninchotirath FW 14 Janepob Phokhi FW 19 Mairon Natan Pereira Maciel Oliveira FW 26 Sarawut Sintupun FW 66 Anan YodsangwalHead Coach: Jongsarith Wuttichuay 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