2020 Thai League 3
The 2020 Thai League 3 is the 4th 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 Pro due to the sponsorship deal with Government Savings Bank. A total of 24 teams would divided into 2 regions including 12 teams in the upper region and 12 teams in the lower region.
Changes from last season
Team changes
Promoted Clubs
Promoted to the 2020 Thai League 2Promoted from the 2019 Thai League 4
- Wat Bot City
- Muang Loei United
- Pattani
- Pathumthani University
Relegated Clubs
Relegated to the 2020 Thai League 4 Bangkok Metropolitan Region
Relegated to the 2020 Thai League 4 Southern Region
- Surat Thani
Renamed Clubs
- Ubon Ratchathani F.C. was renamed to Ubon Kruanapat F.C.
- Ayutthaya F.C. was renamed to Bang Pa-in Ayutthaya F.C.
- Banbueng Phuket City was renamed to Banbueng
Foreign Players
Upper Region
Lower Region
2020 Thai League 3 locations
Stadium and locations (Upper Region)
| Team | Location | Stadium | Capacity |
| Angthong | Angthong | Ang Thong Province Stadium | 6,000 |
| Bang Pa-in Ayutthaya | Ayutthaya | Udomsilwitthaya School Stadium | 2,000 |
| Chachoengsao | Chachoengsao | Chachoengsao Municipality Stadium | 6,000 |
| Chamchuri United | Bangkok | Chulalongkorn University Stadium | 20,000 |
| Chiangrai City | Chiang Rai | Chiangrai Province Stadium | 5,000 |
| Kamphaengphet | Kamphaengphet | Cha Kung Rao Stadium | 2,406 |
| Lamphun Warrior | Lamphun | Mae-Guang Stadium | 3,000 |
| Muang Loei United | Loei | Wangsapung Stadium | 1,230 |
| Muangkan United | Kanchanaburi | Kleebbua Stadium | 5,403 |
| Sakaeo | Sakaeo | Sakaeo PAO. Stadium | 10,000 |
| Ubon Kruanapat | Ubon Ratchathani | Ubonratchathani Sport School Stadium | 2,500 |
| Wat Bot City | Phitsanulok | Phitsanulok Stadium | 3,066 |