2019 Thai League 3
The 2019 Thai League 3 is the 3rd 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.
Changes from last season
Team changes
Promoted Clubs
Promoted to the 2019 Thai League 2- JL Chiangmai United
- MOF Customs United
- Ayutthaya United
- Nakhon Pathom United
- Khon Kaen United
- North Bangkok University
Relegated Clubs
Relegated to the 2019 Thai League 4 Bangkok Metropolitan Region
Relegated from 2018 Thai League 2
- Krabi
- Angthong
Renamed Clubs
- WU Nakhon Si United was renamed to Nakhon Si United
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 |