The 2008 One Night Stand (marketed as One Night Stand: Extreme Rules) was the fourth and final 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 1, 2008, at the San Diego Sports Arena in San Diego, California. One Night Stand was discontinued and replaced by the similarly hardcore-themed Extreme Rules in 2009.

Eight matches were contested at the event, including one dark match that occurred before the live broadcast. The main match on the SmackDown brand was a Tables, Ladders, and Chairs match for the vacant World Heavyweight Championship between Edge and The Undertaker, which Edge won after retrieving the belt suspended above the ring. Per the pre-match stipulation, Undertaker was forced to leave WWE. The predominant match on the Raw brand was a Last Man Standing match for the WWE Championship between Triple H and Randy Orton, which Triple H won after Orton failed to answer the ten-count.

The primary match on the ECW brand was a Singapore Cane match involving Big Show, CM Punk, John Morrison, Chavo Guerrero, and Tommy Dreamer. Big Show won the match after pinning Dreamer to become the number-one contender to the ECW Championship at Night of Champions. Featured matches on the undercard included Shawn Michaels versus Batista in a Stretcher match, John Cena versus John "Bradshaw" Layfield (JBL) in a First Blood match, and Beth Phoenix and Melina in the first-ever women's "I Quit" match.