Antonio Rodrigo Nogueira, aka "Minotauro" (born June 2, 1976 in Vitória da Conquista, Brazil) is a Brazilian mixed martial artist known for his technical mastery of Brazilian Jiu-Jitsu. He competes in the heavyweight division of the Ultimate Fighting Championship, where he is a former UFC Interim Heavyweight Champion.

He holds notable wins over Tim Sylvia, Dan Henderson, Sergei Kharitonov, Mark Coleman, Valentijn Overeem, Gary Goodridge, Ricco Rodriguez, Mirko Filipovic, Jeremy Horn, Josh Barnett, Heath Herring, Semmy Schilt, and Bob Sapp.

He rose to prominence in the Japanese Pride Fighting Championship promotion, where he was the Pride heavyweight champion from November 2001 to March 2003, as well as a Pride FC heavyweight grand prix finalist. He is the first and only fighter to have held Championship titles in both the Pride Fighting Championship promotion and the Ultimate Fighting Championship promotion.

Nogueira has a twin brother, Antonio Rogerio Nogueira, aka "Minotoro", who is also a professional mixed martial artist. Antonio Rodrigo has a distinguishing large scar on the right side of his back from a truck accident as a youth.

At the age of fourteen he was invited by a friend to train Brazilian Jiu-Jitsu under Ricardo de la Riva Goded. He had earlier started training some boxing. In 1999, at age 23, he was awarded with the black belt in both judo and Brazilian Jiu-Jitsu. That same year, he made his mixed martial arts debut against David Dodd in World Extreme Fighting 6, submitting Dodd via crucifix in the first round.

After defeating Nate Schroeder via armbar in WEF 7, he fought in Japan for the Rings promotion's King of Kings 1999 forty eight man tournament held over 3 events where he won three fights before losing by decision to Dan Henderson in the tournament semi-finals. In between the two Rings events in which he competed he defeated Jeremy Horn by decision at WEF 8. Nogueira then entered the King of Kings 2000 forty man tournament held over three events, winning all of his five matches to become the tournament champion.

Nogueira's notable victories in Pride include wins over Dan Henderson, Mark Coleman, Heath Herring, former UFC heavyweight champions Ricco Rodriguez and Josh Barnett, Mirko "Cro Cop" Filipovic, and Bob Sapp.

Following the end of Akira Maeda's Rings federation, Nogueira was signed by Pride. He debuted in July 2001 at Pride 15, quickly submitting Gary Goodridge by triangle choke. In Pride 16, he submitted UFC and Pride Grand Prix champion Mark Coleman by armbar. He was crowned as the inaugural Pride World Heavyweight Champion after defeating Heath Herring by decision.

He next defeating Enson Inoue, then he fought for Antonio Inoki's UFO organisation, scoring his first MMA knockout against Sanae Kikuta.

He then represented Pride at a co-promotion with K-1, Pride Shockwave, against the super heavyweight former American footballer Bob Sapp. Sapp manhandled the much smaller Nogueira, spiking him onto the ring canvas and dominating the fight, until tiring and falling to an armbar submission. His battle with Sapp (who outweighed him by over 150 lb) made him a fan favorite for his seemingly inhuman ability to take punishment before recovering to win.

Dutch karate fighter Semmy Schilt was his next opponent. Again heavily outsized, he scored another victory by triangle choke. He then avenged his sole loss at this point by submitting Dan Henderson who had previously beaten him in Rings.

Nogueira's first Pride title defense was against Russian Sambo champion Fedor Emelianenko at Pride 25 where he suffered his second career loss, a judges' decision after Emelianenko dominated the fight with characteristic ground-and-pound through the guard.

Bouncing back from the loss, he won a decision against former UFC heavyweight champion Ricco Rodriguez. Rodriguez managed to score takedowns and maintain top position, but since Pride's scoring is determined primarily by "effort to finish the fight by KO or submission", Nogueira's multiple submission attempts won him the controversial decision victory.

In November 2003, with heavyweight champion Emelianenko unable to fight due to injuries, Pride elected to crown an interim champion, so top contenders Nogueira and Mirko Filipovic were matched up. Filipovic managed to dominate the first round with his superior striking and landed his trademark left high kick, but in the second round, Nogueira managed to secure a takedown and roll into an armbar to submit Filipovic.

On 25 April 2004 at Pride Total Elimination 2004, the first round of the 2004 Heavyweight Grand Prix, he faced the unbeaten professional wrestler and former judoka Hirotaka Yokoi, who he submitted with the debut of his anaconda choke. He then repeated this against Heath Herring in the next round to advance to the semi finals where he defeated Sergei Kharitonov with his superior boxing to again face Fedor Emelianenko in the finals. The fight was markedly different from their first, with Nogueira able to avoid the damage he suffered from ground-and-pound in their first meeting, but was stopped when Emelianenko suffered a cut after an accidental headbut and could not continue, resulting in a no contest.

Another rematch was required to determine the tournament champion, and was scheduled for Pride Shockwave 2004 on 31 December 2004. Despite Nogueira's improved gameplan and striking technique, he suffered another unanimous decision loss to Emelianenko.

At Pride Critical Countdown 2005 he defeated Polish Olympic judoka Pawel Nastula by strikes and following this, at Pride 31 he beat professional wrestler and fighter Kiyoshi Tamura by armbar for the second time.

He then entered the 2006 Pride Open Weight Grand Prix, progressing to the semi final by defeating fellow Brazilians Zuluzinho and Fabricio Werdum. In the semi final, he faced the American catch wrestler Josh Barnett and lost to a split decision, as both had landed damaging blows and submission attempts without managing to secure a victory. Barnett went on to face Mirko Filipovic in the finals, submitting to punches and kicks to the face.

Nogueira avenged the loss to Barnett with a unanimous decision win in their rematch at Pride Shockwave 2006.

At UFC Fight Night 9 which took place on April 5, 2007 Nogueira was in attendance and was sitting cage side with UFC president Dana White. It was subsequently announced at UFC 69, by White, that Nogueira had joined the UFC, promoted initially as simply "Minotauro" Nogueira, much like the UFC's promotion of Mirko Filipovic as Mirko Cro Cop.

His debut in the Octagon was a third fight with Heath Herring at UFC 73, promoted under various combinations of his name and nickname, but was officially introduced to the audience under his full name and nickname. Nogueira once again defeated Herring, via unanimous decision. During the first round Nogueira was hit with a high kick that sent him to the canvas, in which unofficial judge Eddie Bravo thought the fight could have been stopped. Herring tried to finish but Nogueira was able to hold on and come back with a decision win.

It was announced during the UFC 79 broadcast and subsequent press conference that Nogueira would be fighting Tim Sylvia at UFC 81 for the interim heavyweight championship.

At UFC 81 Nogueira defeated Tim Sylvia in the third round with a guillotine choke to become the interim heavyweight champion. Sylvia knocked Nogueira down in the first round with punches, and Nogueira was unable to get the fight to the ground for the first two rounds. After pulling Sylvia into his half guard in the third round, Nogueira quickly secured a sweep and attempted an armbar which he missed but immediately transitioned into a guillotine choke as Sylvia tried to regain his feet. He is the first fighter to hold both the UFC and Pride heavyweight championships.

The UFC next wanted to schedule Nogueira to face Randy Couture, but Couture had to turn down the fight due to elbow surgery in January 2009. Couture later agreed to fight Nogueira at UFC 101.