The World Chess Championship 2007 was held in Mexico City, from 12 September 2007 to 30 September 2007 to decide the world champion in the board game chess. It was an eight-player, double round robin tournament.
Viswanathan Anand of India won the tournament and the title of World Chess Champion. His winning score was 9 points out of 14, with a total of four wins and 10 draws, and Anand was the only undefeated player in the tournament.
This championship was unusual in that the World Chess Championship was decided by a tournament rather than a match.
The FIDE World Chess Championship 2005 was also a double round robin tournament, but at the time the world title was split, with that tournament being for the FIDE world championship, and with Classical World Champion Vladimir Kramnik refusing to take part. Soon after the 2005 tournament, FIDE announced that the 2007 World Championship would also be a double round robin tournament.
In 2006, FIDE announced the World Chess Championship 2006, to reunify the world chess championship. Because the organization of the 2007 tournament was largely in place, conditions of that match included:
Kramnik won the 2006 match. In June 2007, Kramnik confirmed that he recognized the 2007 tournament as the world championship, while expressing a personal preference for the championship to be decided by a match.
FIDE later announced that future world championships (beginning with the World Chess Championship 2008) would be decided by matches between the champion and a challenger. At the same time FIDE announced that, as compensation for being denied entry to the 2007 tournament, Topalov would have special privileges in the World Chess Championship 2010 cycle.
The top four finishers of the 2005 FIDE World Championship event were granted direct entry into the 2007 event. However, Veselin Topalov, FIDE World Chess Champion 2005, was replaced by Vladimir Kramnik, Classical World Chess Champion, after losing his unification match to him in the 2006 World Championship.