UFC 126: Silva vs. Belfort was a mixed martial arts event held by the Ultimate Fighting Championship on February 5, 2011 at the Mandalay Bay Events Center in Las Vegas, Nevada.

Former Light Heavyweight Champion Vitor Belfort was scheduled to fight Yushin Okami at UFC 122. However, UFC President Dana White said that Belfort would instead challenge Middleweight Champion Anderson Silva for the belt. Belfort was originally scheduled to compete against Silva on January 2, 2010 at UFC 108, but due to an injury sustained by Silva, the fight had to be postponed until February 6, 2010 at UFC 109 and April 10, 2010 at UFC 112, respectively. However, both fights were cancelled.

A bout between Kenny Florian and Evan Dunham was expected for this event. The fight was moved to UFC: Fight For The Troops 2. However, Florian pulled out due to injury on December 6, and Dunham instead fought and lost to Melvin Guillard.

A bout between Jon Fitch and Jake Ellenberger was expected for this event. However Fitch was pulled from the bout and instead fought B.J. Penn at UFC 127. Ellenberger remained on the card and instead fought Carlos Eduardo Rocha.

Anderson da Silva (Portuguese pronunciation: [ˈɐ̃deʁsõ ˈsiwvɐ]; born April 14, 1975) is a Brazilian mixed martial artist. He is the current UFC Middleweight Champion and the promotion's longest reigning champion. With 14 consecutive wins and 9 title defenses, Silva holds the longest winning streak and title defense streak in UFC history.

Silva is ranked as the number one Middleweight in the world by multiple publications, and is the consensus No. 1 pound-for-pound fighter in the world according to ESPN, Sherdog, Yahoo! Sports, MMAFighting.com and other publications. UFC president Dana White has proclaimed Silva as "the greatest mixed martial artist ever."^{[undue weight? – discuss]} Silva is also the last Cage Rage Middleweight Champion and a former Shooto Middleweight Champion. Besides the UFC and Cage Rage, Silva has fought for a number of other MMA promotions including the Pride Fighting Championships, Shooto and Rumble on the Rock.

Although known primarily for his mastery of Muay Thai striking, Silva is also a Brazilian Jiu-Jitsu blackbelt, a rank he earned in 2006 from Antônio Rodrigo Nogueira who follows Gracie Lineage through Carlson Gracie, like Murilo Bustamante and the Brazilian Top Team. He began martial arts training at the age of 14, training Tae kwon do and earning a black belt by the age of 18. He is also a black belt in Judo and a yellow rope in Capoeira.

Vítor Vieira Belfort (Portuguese pronunciation: [ˈvitoʁ viˈejɾɐ bɛwˈfɔʁ]; born April 1, 1977) is a Brazilian mixed martial artist and former UFC Light Heavyweight Champion. Belfort was born in Rio de Janeiro and studied jiu-jitsu with the Gracie family, namely Carlson Gracie. He received a black belt under Carlson and currently trains with Xtreme Couture, fighting in the middleweight division. He is currently ranked as the #3 middleweight in the world by MMA Weekly.

Vítor was born on April 1, 1977 in Rio de Janeiro, Brazil to a French father and a Greek mother. Belfort is married to Joana Prado and together they have three children, a son named Davi (born February 5, 2005), a daughter named Victoria (born October 31, 2007), and a daughter named Kyara (born June 7, 2009).

Belfort also had a small part in a reality show on Brazilian television and appeared next to his wife when she was photographed for the Brazilian edition of Playboy.

On January 9, 2004, Vítor's sister, Priscila Belfort disappeared and the relatives received no information about her. In August 2007, a woman (identified as Elaine Paiva) confessed that she participated in her kidnapping and killing and that she was kidnapped to pay off a four thousand dollar debt Paiva had with drug dealers. Paiva was arrested along with three others alleged to be involved in the kidnapping. The group allegedly buried her body in the woods in Rio de Janeiro where police conducted searches but her remains have never been found. Her family however do not accept this version and believe that Priscila is still alive somewhere. Vítor still maintains a missing sign in the Brazilian version of his website.

Dana White (born July 28, 1969) is the current President of the Ultimate Fighting Championship (UFC), a mixed martial arts organization based in the United States.

Born in Manchester, Connecticut on July 28, 1969, White grew up in Las Vegas, Nevada, Ware, Massachusetts and Levant, Maine. White is a passionate Boston Red Sox fan. During his youth, he bounced back and forth between Boston and Maine. He attended the University of Massachusetts Boston but did not finish; however, while there he did launch a boxing program for inner-city youth.

White has a background as an aerobics instructor. In 1992, White established Dana White Enterprises in Las Vegas. He conducted aerobics classes at three gyms in the Las Vegas area and began managing MMA fighters Tito Ortiz and Chuck Liddell.

While working as a manager, White learned that Semaphore Entertainment Group, the parent company of the UFC, was looking for a buyer for the UFC. White contacted childhood friend Lorenzo Fertitta, an executive at Station Casinos, and a former commissioner of the Nevada State Athletic Commission. Within a month, Lorenzo and his older brother Frank bought the UFC, with White installed as its president. White currently owns about 9% of Zuffa, LLC, the entity the Fertitta brothers created to own and manage the UFC.

Steven Frederic Seagal (born April 10, 1952) is an American action film star, producer, writer, martial artist, guitarist and reserve deputy sheriff. A 7th-dan black belt in Aikido, Seagal began his adult life as an Aikido instructor in Japan. He became the first foreigner to operate an Aikido dojo in Japan.

He later moved to the Los Angeles, California, area where he made his film debut in 1988 in Above the Law. By 1991, he had starred in three successful films, and would go on to achieve greater fame in Under Siege (1992), where he played Navy SEALs counter-terrorist expert Casey Ryback. However both On Deadly Ground (1994, which he directed) and Under Siege 2: Dark Territory (1995) did poorly in theaters. During the later half of the 90s, he starred in three more theatrical films and a direct-to-video The Patriot. Aside from Exit Wounds (2001) and Half Past Dead (2002), his career shifted almost entirely to direct-to-video films (often low budget productions and shot in Europe or Asia). Between 1998 to 2009, he appeared in a total of 22 of these. At the age of 59, he returned to the big screen as Torrez in the 2010 film Machete. As of 2011, he's currently busy with the third season of his reality show Steven Seagal: Lawman.