Ultimate Fighting Championship (UFC) is a U.S.-based mixed martial arts (MMA) organization, recognized as the largest MMA promotion in the world.

The UFC is headquartered in Las Vegas, Nevada and is owned and operated by Zuffa, LLC.

The UFC was started as a tournament to find the world's best fighters irrespective of their style, and was based upon Brazilian vale tudo fighting or No Holds Barred.

Although there were a few limited number of rules at UFC 1, the UFC was initially known as no holds barred fighting, and contests were often violent and brutal. Early UFC fights were less sport than spectacle, which led to accusations of brutality and "human cock fighting" by opponents.

Political pressures eventually led the UFC into the underground, as pay-per-view providers nixed UFC programming, nearly extinguishing the UFC's public visibility.