Thai League 1
| Organising body | Thai League Co., Ltd. |
|---|---|
| Founded | 1996 |
| First season | 1996–97 |
| Country | Thailand |
| Confederation | AFC |
| Number of clubs | 16 |
| Level on pyramid | 1 |
| Relegation to | Thai League 2 |
| Domestic cup(s) | Thai FA Cup Thailand Champions Cup |
| League cup | Thai League Cup |
| International cups | |
| Current champions | Buriram United (11th title) (2024–25) |
| Most championships | Buriram United (11 titles) |
| Most appearances | Rangsan Viwatchaichok (439) |
| Top scorer | Heberty (159) |
| Broadcaster(s) | Advanced Info Service |
| Website | thaileague |
| Current: 2025–26 Thai League 1 | |
The Thai League (Thai: ไทยลีก, pronounced as ไท-หลีก) or Thai League 1 (Thai: ไทยลีก 1, pronounced as ไท-หลีก-หนึ่ง), often referred to as T1, is the highest level of the Thai football league system. Contested by 16 clubs, it operates on a system of promotion and relegation with Thai League 2. Seasons typically run from August to May, with each team playing 30 games: two against each other team, one home and one away. It is sponsored by BYD Auto and therefore officially known as the BYD Sealion 6 League I. In the Thai League, most games are played on Saturday and Sunday evenings, occasionally being played on Wednesday and Friday evening fixtures.