WrestleMania 25 (marketed as The 25th Anniversary of WrestleMania and sometimes written as WrestleMania 25th Anniversary) was the 25th annual WrestleMania 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 April 5, 2009, at Reliant Stadium in Houston, Texas. It was the second WrestleMania held in Houston; the first was WrestleMania X-Seven at the Reliant Astrodome, which was held in April 2001. It was also the last WrestleMania to feature the ECW brand.

Eight matches were held on the event's card, which featured a supercard, a scheduling of more than one main bout. The final match of the night, which was the main match of the Raw brand, was a singles match in which Triple H defeated Randy Orton to retain the WWE Championship. The main match of the SmackDown brand was a triple threat match for the World Heavyweight Championship, which saw John Cena defeat defending champion Edge and Big Show to win the championship. The main match of the ECW brand saw WWE Tag Team Champions The Colóns (Carlito and Primo) from SmackDown defeat the World Tag Team Champions John Morrison and The Miz from ECW in a lumberjack match to unify the two championships; the match took place on the event's pre-show. Another marquee match saw The Undertaker defeated Shawn Michaels to extend his undefeated WrestleMania streak to 17–0. Featured matches on the undercard included Matt Hardy defeating Jeff Hardy in an Extreme Rules match, Chris Jericho defeated the team of Roddy Piper, Ricky Steamboat and Jimmy Snuka, and the annual Money in the Bank ladder match which was won by CM Punk.

Tickets for the event commenced sale to the public on November 8, 2008. For the third consecutive year, WrestleMania broke the record for the highest-grossing pay-per-view in WWE history, grossing US$6.9 million in ticket sales, which included fans from all 50 U.S. states, 24 countries, and seven Canadian provinces. WrestleMania 25 generated approximately 960,000 pay-per-view buys, grossing $21.0 million in revenue. The event pumped an estimated $49.8 million into the local economy and generated $5.7 million in local tax revenue, equating to 600 full-time jobs for the area. With an attendance of 72,744, it is the 8th largest attendance in WrestleMania history.