Lampang won the play-off between the teams in 3rd to 6th place and got promoted to T1.
Thai League 2 2021/22
| Pos | Club | P | W | D | L | F | A | GD | Pts | Form |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 |  Lamphun Warriors | 34 | 22 | 8 | 4 | 66 | 30 | 36 | 74 | |
| 2 |  Sukhothai | 34 | 22 | 7 | 5 | 78 | 44 | 34 | 73 | |
| 3 |  Trat | 34 | 20 | 8 | 6 | 55 | 33 | 22 | 68 | |
| 4 |  Lampang | 34 | 15 | 12 | 7 | 67 | 38 | 29 | 57 | |
| 5 |  Chainat Hornbill | 34 | 15 | 12 | 7 | 58 | 46 | 12 | 57 | |
| 6 |  Phrae United | 34 | 14 | 12 | 8 | 51 | 35 | 16 | 54 | |
| 7 |  Muangkan United | 34 | 14 | 10 | 10 | 70 | 62 | 8 | 52 | |
| 8 |  Udon Thani | 34 | 13 | 8 | 13 | 53 | 58 | -5 | 47 | |
| 9 |  Rayong | 34 | 13 | 7 | 14 | 45 | 41 | 4 | 46 | |
| 10 |  Nakhon Pathom United | 34 | 10 | 12 | 12 | 42 | 47 | -5 | 42 | |
| 11 |  Ayutthaya United | 34 | 10 | 11 | 13 | 40 | 50 | -10 | 41 | |
| 12 |  Ranong United | 34 | 10 | 11 | 13 | 35 | 45 | -10 | 41 | |
| 13 |  Kasetsart | 34 | 9 | 12 | 13 | 32 | 47 | -15 | 39 | |
| 14 |  Chiang Mai | 34 | 10 | 8 | 16 | 39 | 55 | -16 | 38 | |
| 15 |  Customs Ladkrabang United | 34 | 9 | 8 | 17 | 44 | 63 | -19 | 35 | |
| 16 |  Rajpracha | 34 | 7 | 12 | 15 | 34 | 44 | -10 | 33 | |
| 17 |  Khon Kaen | 34 | 5 | 9 | 20 | 32 | 60 | -28 | 24 | |
| 18 |  Navy | 34 | 2 | 5 | 27 | 28 | 71 | -43 | 11 |