2019 Thai League 3
The 2019 Thai League 3 is the third 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 28 teams would divided into 2 regions including 14 teams in the upper region and 14 teams in the lower region.
After Army United FC announced its dissolution in the end of the season, Ranong United was choose as the third team to promoted to Thai League 2.
Changes from last season
Team changes
Promoted clubs
Promoted to the 2019 Thai League 2Promoted from the 2018 Thai League 4
Relegated clubs
Relegated to the 2019 Thai League 4 Northeastern RegionRelegated to the 2019 Thai League 4 Bangkok Metropolitan Region
Relegated from 2018 Thai League 2
Renamed clubs
Moved clubs
- Simork were moved into the Upper Region 2019.
2019 Thai League 3 locations
Stadium and locations (Upper Region)
| Team | Location | Stadium | Capacity |
| Angthong | Angthong | Ang Thong Province Stadium | 6,000 |
| Ayutthaya | Ayutthaya | Udhomseelwitthaya School Stadium | 1,800 |
| Bangkok | Nonthaburi | SCG Stadium | 12,505 |
| Chachoengsao | Chachoengsao | Chachoengsao Municipality Stadium | 6,000 |
| Chiangrai City | Chiang Rai | Chiangrai Province Stadium | 5,000 |
| Kamphaengphet | Kamphaengphet | Cha Kung Rao Stadium | 2,406 |
| Khonkaen United | Khon Kaen | Khonkaen PAO. Stadium | 7,000 |
| Lamphun Warrior | Lamphun | Mae-Guang Stadium | 3,000 |
| Marines Eureka | Chonburi | Sattahip Navy Stadium | 6,000 |
| Muangkan United | Kanchanaburi | Kleebbua Stadium | 5,403 |
| Phrae United | Phrae | Thunghong Municipality Stadium | 4,500 |
| Sakaeo | Sakaeo | Sakaeo PAO. Stadium | 10,000 |
| Simork | Suphanburi | Suphanburi Sports School Stadium | 1,500 |
| Ubon Ratchathani | Ubon Ratchathani | Ubon Ratchathani University Stadium | 2,000 |