UFC 44: Undisputed was a mixed martial arts event held by the Ultimate Fighting Championship at the Mandalay Bay Events Center on the Las Vegas Strip in Paradise, Nevada. Headlining the card was a light heavyweight championship unification bout between Tito Ortiz and Randy Couture.

UFC 47: It's On! was a mixed martial arts event held by the Ultimate Fighting Championship at the Mandalay Bay Events Center in Las Vegas, Nevada. The title "It's On!" refers to Chuck Liddell and Tito Ortiz' long running negotiations leading up to the fight.

UFC 84: Ill Will was a mixed martial arts event held by the Ultimate Fighting Championship (UFC) on May 24, 2008, at the MGM Grand Garden Arena in Las Vegas, Nevada. The card featured the return of Sean Sherk, who was suspended and stripped of his UFC lightweight title after he tested for steroids at UFC 73. He faced B.J. Penn, who had since won the vacated title.

UFC 81: Breaking Point was a mixed martial arts (MMA) event held by the Ultimate Fighting Championship (UFC) at the Mandalay Bay Events Center in Las Vegas, Nevada. The event featured Tim Sylvia and Antonio Rodrigo "Minotauro" Nogueira for UFC's Interim World Heavyweight Championship.

UFC 52: Couture vs. Liddell 2 was a mixed martial arts event held by the Ultimate Fighting Championship on April 16, 2005, at the MGM Grand Arena in Las Vegas, Nevada. The event was broadcast live on pay-per-view in the United States and Canada, and later released on DVD.

UFC 39: The Warriors Return was a mixed martial arts event held by the Ultimate Fighting Championship on September 27, 2002, at the Mohegan Sun Arena in Uncasville, Connecticut. The event was broadcast live on pay per view in the United States, and was the first UFC event to be released on DVD.

UFC 43: Meltdown was a mixed martial arts event held by the Ultimate Fighting Championship on June 6, 2003, at the Thomas and Mack Center in Las Vegas, Nevada. Headlining the card was the Interim Light Heavyweight Championship match between Randy Couture and Chuck Liddell.

UFC 49: Unfinished Business was a mixed martial arts event held by the Ultimate Fighting Championship at the MGM Grand Arena in Las Vegas, Nevada. It featured the anticipated rubber match between Light Heavyweight Champion Vitor Belfort and Randy Couture, following a disappointing doctor's stoppage in their last encounter at UFC 46.

UFC 85: Bedlam was a mixed martial arts event held by the Ultimate Fighting Championship (UFC) on June 7, 2008, at The O2 Arena in London, United Kingdom. The main event was ultimately changed to Matt Hughes against Thiago Alves. Hughes took the fight on short notice as a favor to the UFC and Alves came in four pounds overweight.

UFC 83: Serra vs St-Pierre 2 was a mixed martial arts event held by the Ultimate Fighting Championship. The event was held on April 19, 2008, at the Bell Centre in Montreal, Quebec, Canada. UFC 83 was the UFC's first event in Canada. It was headlined by UFC Welterweight Champion Matt Serra and UFC Interim Welterweight Champion Georges St. Pierre in a match to unify the championship.

UFC 82: Pride of a Champion was a mixed martial arts (MMA) event that took place on 1st March, 2008 at the Nationwide Arena in Columbus, Ohio. The main event was a UFC & Pride FC middleweight title unification match between UFC middleweight champion Anderson Silva and PRIDE FC welterweight champion Dan Henderson.

UFC 40: Vendetta was a mixed martial arts event held by the Ultimate Fighting Championship on November 22, 2002, at the MGM Grand Arena on the Las Vegas Strip in Paradise, Nevada. The event was broadcast live on pay per view in the United States, and later released on DVD. UFC 40 contained one of the biggest, most important and most anticipated fights in UFC history, a UFC Light Heavyweight Championship fight between rivals Tito Ortiz and Ken Shamrock. Shamrock, a popular legendary fighter and former champion from the UFC's early years, was returning to the UFC for the first time since 1996. The fight was coined "the biggest fight in UFC history" by the UFC during the event.

UFC 50: The War of '04 was a mixed martial arts event held by the Ultimate Fighting Championship at the Trump Plaza in Atlantic City, New Jersey. Headlining the card were Tito Ortiz and Patrick Côté. Côté was a late replacement for Lion's Den fighter Guy Mezger, who pulled out of the event due to a medical condition. It also featured the Middleweight debut of future champion Rich Franklin.

UFC 51: Super Saturday was a mixed martial arts event held by the Ultimate Fighting Championship on February 5, 2005 (Super Bowl weekend) at the Mandalay Bay Events Center in Las Vegas, Nevada.

UFC 38: Brawl at the Hall was a mixed martial arts event held by the Ultimate Fighting Championship. It took place at the Royal Albert Hall in London, England, on July 13, 2002. The event was seen on pay per view in the United States, and was later released on home video.

UFC 37.5: As Real As It Gets was a mixed martial arts event held by the Ultimate Fighting Championship at the Bellagio Hotel and Casino in Las Vegas, Nevada on June 22, 2002.

UFC 45: Revolution was a mixed martial arts event held by the Ultimate Fighting Championship at the Mohegan Sun Casino in Uncasville, Connecticut. This event marked the 10th anniversary of the UFC and to celebrate the anniversary the UFC inaugurated its Hall of Fame, with Royce Gracie and Ken Shamrock as the first inductees.

UFC 48: Payback was a mixed martial arts event held by the Ultimate Fighting Championship at the Mandalay Bay Events Center in Las Vegas, Nevada. The featured contestants of the evening were Ken Shamrock and Kimo Leopoldo, who had met once before in 1996 at UFC 8, with Shamrock reigning victorious.

UFC 100 was a mixed martial arts event produced by the Ultimate Fighting Championship (UFC) on July 11, 2009, in Las Vegas, Nevada. The main event was a rematch between UFC Heavyweight Champion Brock Lesnar and Interim UFC Heavyweight Champion Frank Mir.

UFC 42: Sudden Impact was a mixed martial arts event held by the Ultimate Fighting Championship at the American Airlines Arena in Miami, Florida. UFC 42 was the first UFC event to take place in Florida. Headlining the event was a Welterweight Title bout between Matt Hughes and Sean Sherk. UFC 42 also marked the first UFC appearance of future Middleweight Champion Rich Franklin.