Controversy over George W. Bush's military service in the Air National Guard was an issue that first gained widespread public attention during the 2004 presidential campaign. The controversy centered on Texas Air National Guard, why he lost his flight status, and whether he fulfilled the requirements of his military service contract.

The Killian documents controversy involved six documents containing allegations about President George W. Bush's service in the Texas Air National Guard in 1972–73, allegedly typed in 1973. Dan Rather presented four of these documents as authentic in a 60 Minutes II broadcast aired by CBS on September 8, 2004, less than two months before the 2004 presidential election, but it was later found that CBS had failed to authenticate them. Several typewriter and typography experts soon concluded that they were forgeries. Lieutenant Colonel Bill Burkett provided the documents to CBS, but he claims to have burned the originals after faxing them copies.