List of WWE pay-per-view events in the context of "WrestleMania 21"

The 2009 Royal Rumble was the 22nd annual Royal Rumble professional wrestling pay-per-view (PPV) event produced by World Wrestling Entertainment (WWE). It was held for wrestlers from the promotion's Raw, SmackDown, and ECW brand divisions. The event took place on January 25, 2009, at the Joe Louis Arena in Detroit, Michigan. As has been customary since 1993, the Royal Rumble match winner received a world championship match at that year's WrestleMania. For the 2009 event, the winner received their choice to challenge for either Raw's World Heavyweight Championship, SmackDown's WWE Championship, or the ECW Championship at WrestleMania 25.

Five professional wrestling matches were featured on the event's supercard, a scheduling of more than one main event. The main event was the 2009 Royal Rumble match, which featured wrestlers from all three brands. Raw's Randy Orton, the eighth entrant, won the match by last eliminating SmackDown's Triple H, the seventh entrant. The primary match on the Raw brand was John Cena versus John "Bradshaw" Layfield (JBL) for the World Heavyweight Championship, which Cena won to retain the title. The primary match on the SmackDown brand was a No Disqualification match between Jeff Hardy and Edge for the WWE Championship, which Edge won to win his fourth and last WWE Championship. The predominant match on the ECW brand was between Jack Swagger and Matt Hardy for the ECW Championship, which Swagger won to retain. This event also marked the first appearance of Rob Van Dam in WWE since One Night Stand in June 2007.

The 2002 Royal Rumble was the 15th annual Royal Rumble professional wrestling pay-per-view (PPV) event produced by the World Wrestling Entertainment. It took place on January 20, 2002, at the Philips Arena in Atlanta, Georgia. Six matches were contested at the event.

As has been customary since 1993, the Royal Rumble match winner received a world championship match at that year's WrestleMania. For the 2002 event, the winner received a match for the Undisputed WWE Championship at WrestleMania X8—this was the last Royal Rumble until 2014 to feature one world championship. The main event was the 2002 Royal Rumble match, which was won by Triple H, who last eliminated Kurt Angle. In other prominent matches, Chris Jericho defeated The Rock to retain the Undisputed WWE Championship, Ric Flair wrestled his first WWE match in 9 years by defeating Vince McMahon in a Street Fight, and William Regal defeated Edge to win the WWE Intercontinental Championship.

WrestleMania 2000, also known as WrestleMania 16, was a professional wrestling pay-per-view (PPV) event produced by the World Wrestling Federation (WWF, now WWE). It was the 16th annual WrestleMania, and took place on April 2, 2000, at the Arrowhead Pond of Anaheim in Anaheim, California. This was the second WrestleMania at this venue, after WrestleMania XII in 1996. A total of nine matches were contested on the event's card.

The main event was a four-way elimination match for the WWF Championship involving reigning champion Triple H, The Rock, Mick Foley, and The Big Show, which Triple H won after last eliminating The Rock; in the first time a heel won the main event of WrestleMania. Main matches on the undercard included a triangle ladder match for the WWF Tag Team Championship involving Edge and Christian, The Hardy Boyz, and The Dudley Boyz, and a two-fall triple threat match for the WWF Intercontinental, and European Championships involving Kurt Angle, Chris Jericho, and Chris Benoit.

WrestleMania X8, also known as WrestleMania 18, was a 2002 professional wrestling pay-per-view (PPV) event produced by the World Wrestling Federation (WWF, now WWE). It was the 18th annual WrestleMania and took place on March 17, 2002, at the SkyDome in Toronto, Ontario, Canada, the second WrestleMania at that venue after WrestleMania VI in 1990. The event marked the last WrestleMania of the Attitude Era and the last one held before the introduction of the brand extension just a week after the event. This was the last WrestleMania to be held outside the United States until 2027 when it will be hosted in Saudi Arabia and the venue, renamed to Rogers Centre in 2005, would not host another WWE event until 2025 when Elimination Chamber took place.

Eleven matches were contested at the event. The Rock defeated Hollywood Hulk Hogan in the main attraction dubbed "Icon vs. Icon", in what was Hogan's first WrestleMania since WrestleMania IX in 1993. In the final match, Triple H defeated Chris Jericho to win the Undisputed WWF Championship. In other prominent matches on the undercard Stone Cold Steve Austin defeated Scott Hall, The Undertaker defeated Ric Flair in a no disqualification match, and Rob Van Dam defeated William Regal to win the WWF Intercontinental Championship.

WrestleMania XX was a 2004 professional wrestling pay-per-view (PPV) event produced by World Wrestling Entertainment (WWE). It was the 20th annual WrestleMania and took place on March 14, 2004, at Madison Square Garden in New York City, New York, held for wrestlers from the promotion's Raw and SmackDown! brand divisions. This was the third WrestleMania at Madison Square Garden, after WrestleMania I in 1985 and WrestleMania X in 1994, and the fourth of six WrestleManias in the New York metropolitan area, alongside WrestleMania I, 2, X, 29, and 35. This is the most recent WrestleMania to be held at Madison Square Garden and its calendar date of March 14 is the earliest date for a WrestleMania.

The match card featured two billed main events. The card's final match, which was the main event for the Raw brand, was a triple threat match for the World Heavyweight Championship, which saw champion Triple H defending the title against Shawn Michaels, and that year's Royal Rumble match winner, Chris Benoit, who won the match, making Triple H submit via the Crippler Crossface, resulting in his first and only world championship in WWE. The main event for the SmackDown! brand featured Eddie Guerrero versus Kurt Angle for the WWE Championship, which Guerrero won by a Small Package pin. The event also featured the return of The Undertaker in his Deadman persona, who defeated Kane after a Tombstone Piledriver. John Cena made his in-ring WrestleMania debut at the event, defeating Big Show to win his first title in WWE, the WWE United States Championship.

The 2007 One Night Stand (marketed as One Night Stand: Extreme Rules) was the third annual One Night Stand professional wrestling pay-per-view (PPV) event produced by World Wrestling Entertainment (WWE). It was held for wrestlers from the promotion's Raw, SmackDown!, and ECW brand divisions. The event took place on June 3, 2007, at the Jacksonville Veterans Memorial Arena in Jacksonville, Florida. While the previous two years' events were held primarily as reunion shows for Extreme Championship Wrestling (ECW) alumni, the 2007 event was promoted as a WWE event with wrestlers from all three brands participating as following WrestleMania 23, brand-exclusive PPVs were discontinued.

The main match on the Raw brand was John Cena versus The Great Khali in a Pinfalls Count Anywhere match for the WWE Championship. Cena won the match and retained the WWE Championship after pinning Khali following an FU off a crane onto the arena floor. The featured match on the SmackDown! brand was Edge versus Batista in a Steel Cage match for the World Heavyweight Championship, which Edge won after escaping the cage.