Carlsen played in the 2013 Candidates Tournament, which took place in London, from 15 March to 1 April. He finished with +5−2=7, and won the tournament on tiebreak over Vladimir Kramnik. As a result, he earned the right to challenge Anand for the World Championship.
In 2013, Time magazine named Carlsen one of the 100 most influential people in the world.
Garry Kasparov, who coached Carlsen from 2009 to 2010, said that Carlsen has a positional style similar to that of past world champions such as Anatoly Karpov, José Raúl Capablanca, and Vasily Smyslov, rather than the tactical style of Alexander Alekhine, Mikhail Tal, and Kasparov himself. In a 2013 interview, Peter Heine Nielsen said: "The days of big novelties are over, and that fits Magnus' style well." According to Carlsen, however, he does not have any preferences in playing style. Kasparov said in 2013 that "Carlsen is a combination of Karpov [and] Fischer. He gets his positions [and] then never lets go of that bulldog bite. Exhausting for opponents." Carlsen has also stated that he follows in the traditions of Karpov and Fischer, but additionally mentions Reuben Fine as a player who "was doing in chess similar to what I am doing".
In October 2013, Carlsen co-founded a company, Play Magnus AS. Based in Oslo, Norway, Play Magnus' first product was an iOS app, called Play Magnus, that allows the user to play a chess engine created using a database of thousands of Carlsen's recorded games from the age of five. The apps Magnus Trainer and Magnus Kingdom of Chess followed in 2016 and 2018, respectively. In March 2019, Play Magnus joined forces with Chess24.com. In September 2019, the group acquired Chessable, an interactive chess learning platform and marketplace. Carlsen's goal is to use Play Magnus and its group of chess companies as a platform to encourage more people to play chess.
In August 2013, Carlsen became an ambassador for Nordic Semiconductor, and in November was selected as one of the "sexiest men of 2013" by Cosmopolitan. In 2017, Carlsen made a special guest appearance on The Simpsons, in an episode where Homer's chess history is revealed.
Carlsen is an avid fan of football, with Real Madrid CF as his favourite club. In recognition of becoming world chess champion, he took the honorary kick-off in a La Liga game between Real Madrid and Real Valladolid on 30 November 2013. Carlsen also follows the Premier League and plays fantasy football. In December 2019, he reached the No. 1 spot on the Fantasy Premier League game, ahead of seven million other players.