Thai League 1
The Thai League or Thai League 1, 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.
History
Origins (1916–1995)
Thailand has had organized football competition since 1916, when the Football Association of Thailand established the first official tournament. The Kor Royal Cup served as the premier football competition from 1916 to 1995, operating as a knockout tournament rather than a league system. During this 79-year period, the tournament underwent several format changes, initially featuring only Bangkok-based clubs before expanding to include provincial teams in the 1960s.The transition from cup to league format was driven by the need to modernize Thai football and meet Asian Football Confederation standards for professional competitions. The semi-professional nature of the Kor Royal Cup, with its limited schedule and lack of home-and-away fixtures, was seen as inadequate for developing Thai football to international standards.
Foundation (1996–2007)
Thai League was introduced in 1996 by the Football Association of Thailand under the name Thailand Soccer League. Eighteen clubs who earlier competed for the Kor Royal Cup were registered to play in the first edition of a double round-robin league system. Bangkok Bank was crowned as the first champion of the 1996–97 Thailand Soccer League.The Thai League originally had 10 to 12 clubs each season until Thai [Premier League 2007|2007], when it was expanded to 16 clubs. At the end of each season, the three bottom placed clubs are relegated to the Thai Division 1 League.
Leagues integration (2007)
Most of Thai League clubs in that time were the organisation of government authorities club that based in Greater Bangkok and Metropolitan. Meanwhile, the other local clubs had competed in the semi-pro league called the Provincial League. Thai Premier League faced the issue of low attendance and lack of local loyalties while the Provincial league suffered the financial issue. In 2007, Thai League was integrated with Provincial League completely. Chonburi from the Provincial League was the first champion of the new Thailand Premier League in the 2007 season.Modern era (2009–present)
In 2009 season, there were significant changes in the lead to the new era of the Thai Premier League. Asian Football Confederation declared the regulations for the associations that have the intention to send the clubs to compete in the AFC Champions League starting from 2011. Football Association of Thailand had to establish Thai Premier League Co., Ltd. and forced the clubs in the top league to complete AFC Club License Criteria otherwise Thai clubs will not eligible to play in the Champions League. Clubs were forced to separate themselves from the parent organisations and registered as the independent football authorities.The massive changes occurred in that season. Thailand Premier League renamed to Thai Premier League. Two times league champion Krung Thai Bank failed to complete the new regulations. The organisation decided to sell the club. The club was acquired by Boon Rawd and rebranded to be Bangkok Glass. Bangkok University had expelled their football club section. The club rebrand itself to Bangkok United since then. The organisation-based clubs had to relocate to find the local supporters to backup the clubs. Osotspa changed their home stadium to Saraburi Province, TOT moved to play in Kanchanaburi, Royal Navy played in Rayong Province while Thailand Tobacco Monopoly integrated to Samut Sakhon Province and rebranded to TTM Samut Sakhon.
Muangthong United were promoted from Thai Division 1 League in that season and won Thai Premier League in their first year in the top league.
Thailand Clasico
Thailand Clasico or The Classic Match of Thailand is the matchup between Muangthong United and Chonburi. It is the matchup that presents Thai football in the modern era. The name was given to the encounter of two teams due to the hype and massive atmosphere around the match. The first encounter between them happened in the 2009 Thai Premier League season. On 30 May 2009, Chonburi that was regarded as the best club in Thailand at that moment hosted the new powerhouse who were just promoted from Division 1 Muangthong United. The match was played at Nong Prue Stadium, Pattaya. Before the match, Chonburi was the leader in the table after 10 matches of the season while Muangthong followed in second with one less point. Chonburi made the lead by 2–0 in the first thirty minutes but Muangthong bounced back to win by the 5–2 result at the end.The first invincible
In the 2012 season, Muangthong United under Serbian head coach Slaviša Jokanović, had become the first club in the league history that completed the season with an unbeaten record. Muangthong finished at the top of the final standing with 25 wins and 9 draws.Buriram dominance
The Buriram Dominance refers to the 2013 to 2015 season, when Buriram United won Thai Premier League in three consecutive seasons as the first club in the league history. The three titles in that period included two invincible titles which Buriram United completed Thai Premier League campaign unbeaten in 2013 and 2015 season.Rebranding (2017)
In 2017, Football Association of Thailand decided to rebrand Thai Premier League into Thai League 1. Since its inception in 1996 the Thai Premier League has relied upon local sponsorship. Re-branding initiatives seek to foster an international identity for the Thai and elevate the league globally through commitment to world-class level management and marketing which incorporates multifaceted promotion through various media to draw attention to league competition and cups. This rebranding earned the Good Design Award in the Brand Identity branch from the Japan Institute of Design Promotion.The rebranding of the Thai League from 2017 to 2023 has been well received in terms of viewership with a large number of visitors to the stadium and watching through live broadcasts but in terms of benefits, the Thai League receives royalties for broadcasting live matches at an ever-lower value after the end of season 2022-23 Thai League is only worth 50 million baht, an amount that risks collapsing the league.
Thai League Revolution (2023)
On Tuesday, June 27, 2023, Kornwee Phrissanantakul, Acting Chief Executive Officer of Thai League Company Limited and Patis Supapong, Secretary General of the Football Association of Thailand in the Royal Patronage has called a meeting of representatives of 16 Thai League member clubs to find a solution and offer suggestions after the auction to buy Thai League licenses is not as expected. The recommendation from the majority of 16 teams is for all 16 teams to manage and find benefits among themselves, which will bring information and details to the Association Executive Council meeting on Monday 3 July.On July 18, 2023, the Thai League club meeting launched the #SAVETHAILEAGUE initiative to raise funds for Thai League clubs directly from football fans by purchasing a package to watch live broadcasts directly from your favorite team to address the issue of low Thai League values. While the #SAVETHAILEAGUE campaign has yet to increase the value of the Thai League, the overall valuation of the league remains uncertain.
Sponsorship
The Thai League has been sponsored since 1996 until 2003 and has been sponsored again since 2010. The sponsor has been able to determine the league's sponsorship name. The list below details who the sponsors have been and what they called the competition:| Period | Sponsor | Brand |
| 1996–1997 | Johnnie Walker | Johnnie Walker Thailand Soccer League |
| 1998–2000 | Caltex | Caltex Premier League |
| 2001–2003 | Advanced Info Service | GSM Thai League |
| 2003–2005 | No sponsor | Thai League |
| 2006–2008 | No sponsor | Thailand Premier League |
| 2009 | No sponsor | Thai Premier League |
| 2010–2012 | Sponsor Energy Drink | Sponsor Thai Premier League |
| 2013–2015 | Toyota | Toyota Thai Premier League |
| 2016–2021 | Toyota | Toyota Thai League |
| 2022–2025 | Toyota | Hilux Revo Thai League |
| 2025–present | BYD Auto | BYD Sealion 6 League 1 |
Match balls
The 2021–2028 season uses the Molten match balls.Clubs
There are 16 clubs in the league, with three promoted teams from Thai League 2 replacing the three teams that were relegated from the 2024–25 season.Khonkaen United, Nakhon Pathom United and Nongbua Pitchaya were relegated at the end of the 2024–25 season after finishing in the bottom three places of the table. They were replaced by 2024–25 Thai League 2 champions Chonburi. They were joined by runners-up Ayutthaya United, who also got promoted back after relegated two season before, and Kanchanaburi Power, promotion plays-off winner.
Current clubs
Champions
The Invincibles
Unbeatable champions:- Muangthong United in 2012
- Buriram United in 2013 and 2015
Records
All-time top scorers
| Rank | Player | Years | Goals | Apps | Ratio | ||||
| 1 |  #expr:159/249round2Most appearances
|
