UFC 129: St-Pierre vs. Shields was a mixed martial arts event held by the Ultimate Fighting Championship on Saturday, April 30, 2011 at Rogers Centre in Toronto, Ontario.

The event was the sixth that the UFC has hosted in Canada and the first mixed martial arts event in Ontario since the sport was legalized in the province in August 2010. The Toronto event was originally titled UFC 131 by the promotion, but later changed to UFC 129 as its early 2011 schedule started to fall more firmly into place.

It was the largest UFC event in North American history and coincided with a two-day UFC Fan Expo at the Direct Energy Centre. UFC officials had originally planned for the Rogers Centre to be configured to hold 42,000 fans for UFC 129. The UFC put those tickets on sale to UFC Fight Club members in a special pre-sale on February 10, 2011, selling nearly all of them. They released and sold more tickets the following day to UFC newsletter subscribers in a second special pre-sale. UFC 129 then sold out when tickets went on sale to the general public on February 12, with officials scrambling to up the number of seats to 55,000. Selling out all 55,000 tickets for gate revenues exceeding $11 million, the event shatters both MMA attendance and gate records in North America.

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.

Randy Duane Couture (pronounced /koʊˈtʊər/; born June 22, 1963) is an actor, retired American mixed martial artist, collegiate and Greco-Roman wrestler. During his tenures in the Ultimate Fighting Championship (UFC), Couture became a three-time UFC Heavyweight Champion, two-time UFC Light Heavyweight Champion, an Interim UFC Light Heavyweight Champion, and was the UFC 13 Heavyweight Tournament Winner. Couture is the first fighter to hold two UFC championship titles in two different divisions (heavyweight and light heavyweight). Couture has competed in a record 15 title fights. He holds the most title reigns in the UFC with five. His last fight with Lyoto Machida marked his 24th fight in the UFC, the third most amount of fights in the UFC (Tito Ortiz is first with 26 and Matt Hughes is second with 25). Couture is one of the first members of the UFC Hall of Fame. He is the only person over the age of 40 to have won a UFC championship fight, having done so four times.^{[citation needed]}

Couture was an Olympic wrestling alternate and has lived in Corvallis, Oregon, throughout much of his career, where he served as an assistant wrestling coach and a strength and conditioning coach for Oregon State University. He established Team Quest with Matt Lindland and Dan Henderson, a training camp for fighters, based out of Gresham, Oregon, and headed by coach Robert Folis. In 2005, Couture moved to Las Vegas, where he opened his own extensive chain of gyms under the name Xtreme Couture. He currently trains at his Las Vegas-based gym. Couture partnered with Bas Rutten in the opening of Legends Gym in Hollywood, California.

Jake Shields (born January 9, 1979) is an American mixed martial artist who is currently fighting in the middleweight division of the UFC. He is the last Rumble on the Rock 175 lb (79 kg) champion. He is the first and last Elite XC Welterweight Champion. He is also the former Shooto Welterweight Champion and is the former Strikeforce Middleweight Champion. Shields is currently ranked as the #8 welterweight fighter in the world by MMAWeekly.

He has trained extensively with Cesar Gracie, and is a member of the "Elite Pack" which includes fellow Cesar Gracie students Dave Terrell, Nick Diaz, Nate Diaz and Gilbert Melendez. After his loss to Akira Kikuchi he won 15 consecutive fights over 6 years, until his loss to Georges St-Pierre. Among his victories are wins over Martin Kampmann, Dan Henderson, Paul Daley, Hayato Sakurai, Jason 'Mayhem' Miller, Carlos Condit, Yushin Okami, and Yoshihiro Akiyama. He describes his style as American Jiu jitsu.

Shields was raised near Mountain Ranch California in the Sierra Nevada Mountains. He was home schooled up to junior high. He and his two older brothers grew up at the end of a dirt road on the rim of the Jesus Maria Canyon. Their nearest friends were a 45 minute hike down one side of the canyon and up the other. Their activities included mountain biking, wild caving, snowboarding, clearing brush, bucking firewood, climbing mountains, exploring the high country, and wrestling.

Mark "The Machine" Hominick (born July 22, 1982) is a Canadian mixed martial artist, former TKO Featherweight Champion, and current UFC fighter.

As a teen he attended Ingersoll District Collegiate Institute. He was trained by the late great MMA striking coach Shawn Tompkins with Sam Stout at The Adrenaline Training Center in London, Ontario, where he also works as an instructor.

Hominick has fought at both Featherweight and Lightweight during his professional career. He has appeared in many organizations including the UFC, Affliction, TKO, and WEC.

He was scheduled to fight Deividas Taurosevičius on October 10, 2009 at WEC 43., but was forced to withdraw due to an injury.

Hominick was scheduled to face Yves Jabouin on January 10, 2010 at WEC 46, but Jabouin was forced off the card with an injury. Hominick instead faced WEC newcomer Bryan Caraway, winning by submission in the first round.

The fight eventually took place on June 20, 2010 at WEC 49. Hominick won via TKO in the second round. They both won a Sherdog award for best round of 2010.