2011 Thai Premier League (known as Sponsor Thai Premier League for sponsorship reasons) was the 15th season of the Thai Premier League since its establishment in 1996. A total of 18 teams are competing in the league due to a two team expansion, with Muangthong United as the defending champions. The season started on 12 February 2011 and is generally broken down into 2 legs. The first leg being played from February to early June with the second leg taking place from late July to November. During the league break, the opening rounds of the FA Cup and League Cup take place.