The 2004 Armageddon was the fifth Armageddon professional wrestling pay-per-view (PPV) event produced by World Wrestling Entertainment (WWE). It was held exclusively for wrestlers from the promotion's SmackDown! brand division. The event took place on December 12, 2004, at the Gwinnett Center in the Atlanta suburb of Duluth, Georgia. Nine professional wrestling matches were scheduled on the event's card.

All four championships exclusive to the SmackDown! brand were contested for; one was lost while the other three were retained. The main event was a Fatal-Four Way match for the WWE Championship involving Eddie Guerrero, champion John "Bradshaw" Layfield (JBL), Booker T and The Undertaker, which JBL won after pinning Booker T. One of the predominant matches on the undercard was The Big Show versus Kurt Angle, Mark Jindrak, and Luther Reigns in a Handicap match. Big Show won the match after pinning Jindrak following an F-5. Another primary match on the card was John Cena versus Jesús in a Street Fight for the WWE United States Championship, which Cena won by pinfall after executing an FU.