The Thai Premier League (Thai: ไทยพรีเมียร์ลีก) is a Thai professional league for association football clubs. At the top of the Thai football league system, it is the country's primary football competition. Contested by 18 clubs, it operates on a system of promotion and relegation with Thai Division 1 League. The Thai Premier League is a corporation in which the 18 member clubs act as shareholders. Seasons run from March to October, with teams playing 34 games each totalling 306 games in the season. It is sponsored by Toyota and therefore officially known as the Toyota Thai Premier League. In the Thai Premier League, most of the games are played during Saturdays and Sundays, with a few games played during the weekdays.
Before the inception of Thai Premier League, the highest level of club football was the Kor Royal Cup (Thai: ถ้วย ก.) which was contested in a tournament format from 1916 to 1995. Thai Premier League was introduced in 1996 by the Football Association of Thailand (FAT), with 18 clubs who earlier competed for the Kor Royal Cup, in a double round robin league system.
The Thai Premier league originally had 10 to 12 clubs each season until 2007, when it was expanded to 16 clubs. At the end of each season, three bottom placed clubs are relegated to the Thai Division 1 League.
And also in 2007, Thai Premier League was combined with Provincial League completely. Chonburi was the first club from Provincial League that was the champion of Thai Premier League in 2007 season.
There are 18 clubs in the Thai Premier League. During the course of a season, which lasts from March to October, each club plays the others twice, once at their home stadium and once at that of their opponents, for a total of 34 games. Teams receive three points for a win and one point for a draw. No points are awarded for a loss. Teams are ranked by total points, then head-to-head, then goal difference, and then goals scored. At the end of each season, the club with the most points is crowned champion. If points are equal, the head-to-head, the goal difference and then goals scored determine the winner. If still equal, teams are deemed to occupy the same position. If there is a tie for the championship, for relegation, or for qualification to other competitions, a play-off match at a neutral venue decides rank. The three lowest placed teams are relegated into the Thai Division 1 League and the top three teams from the Division 1 League are promoted in their place.
In the past The Champion will play in AFC Champions League Playoffs and AFC Cup for the Champion of Thai FA Cup. Due to reforms from the AFC for the AFC Champions League and AFC Cup format, there will be no more a direct qualification spot for the AFC Champions League for the Thai Champion, for the time being. From 2012 Thai clubs has 1 automatic spot to the group stage and 1 playoff spot for the Thai FA Cup Winners.
Thai Premier League All-Star Exhibition game
The Thai Premier 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: