Mtel Masters was an annual super-GMchess tournament held between 2005 and 2009 in Sofia, Bulgaria, sponsored and organized by the Bulgarian mobile network operator, M-Tel. The tournament was held as a double round-robin at the five-starGrand Hotel Sofia.
The first edition of the tournament took place between 11 and 22 May 2005 as part of M-Tel's tenth anniversary celebrations and with the participation of top chess players such as Viswanathan Anand, Veselin Topalov, Vladimir Kramnik, Michael Adams, Judit Polgár and Ruslan Ponomariov. M-Tel Masters 2005 was classified in FIDE's Category 20 and was named the strongest tournament of 2005 according to the average Elo rating of the participants of 2744. The winner of the tournament was the Bulgarian Veselin Topalov, with the award being conferred by President Georgi Parvanov.
The 2006 tournament took place between 10 May and 21 May and was attended by Veselin Topalov, Viswanathan Anand, Ruslan Ponomariov, Peter Svidler, Étienne Bacrot and Gata Kamsky. Brazilian writer Paulo Coelho played the token initial move of the 2006 tournament, which was officially opened by the President of Bulgaria, Georgi Parvanov.
Topalov won the tournament for the second time after a decisive comeback from a somewhat hesitant start. He recorded four consecutive wins in the final rounds to clinch the M-Tel Masters 2006 first place with 6½ points, also defeating his main rival Gata Kamsky in the penultimate round.
M-Tel Masters' 2007 edition was held between 9 May and 20 May and featured Veselin Topalov, Liviu-Dieter Nisipeanu, Shakhriyar Mamedyarov, Gata Kamsky, Michael Adams and Krishnan Sasikiran. Topalov won the tournament for a third consecutive time in a dramatic fashion, defeating the then-current leader Sasikiran in the final round.
The 2008 M-Tel Masters was held 8–18 May. Vasyl Ivanchuk won by a wide margin. Ivanchuk won his first five games, lost no games, and had a positive score against every other player. Veselin Topalov, who had won the tournament the three previous years, was second.