Infinite Challenge (a.k.a. Muhan Dojeon; Hangul: 무한도전; Hanja: 無限挑戰; abbreviated Mudo) is a Korean television entertainment program, distributed and syndicated by MBC. As of June and July 2009, it still has the largest market share for its timeslot, between 13.8 percent and 19.7 percent of Korean television viewers watched Muhan Dojeon at 6:40 PM every Saturday night. This makes it the top free-to-air television program on Saturday evening, and also the most viewed non-drama program in South Korea every week (excluding special sporting events, since November 2006, with the exception of January 2009, April and May 2010). It has kept the same scheduled time, since first airing in 2005. Since 2009, it lasts for roughly 70 minutes, excluding ten minutes of advertising. Episodes are also frequently rerun on several Korean cable broadcasting channels. Since February 19, 2011 (237th episode), this programme has been aired with High Definition(HD).

Infinite Challenge has been reported as the first "Real-Variety" show in Korean television history. The program is largely unscripted, and follows a similar format of challenge-based Reality Television programs, familiar to the audiences in the West, but the challenges are often silly, absurd, or impossible to achieve, so the program takes on the aspect of a satirical comedy variety show, rather than a more standard reality or contest program. In order to achieve its comedic purposes its 6 hosts and staff continuously proclaim, the elements of this show are the 3-Ds, Dirty, Dangerous, and Difficult.