- Box Office Bomb: Despite doing relatively well at the box office, with $9 million out of a $6 million budget, it was unable to recoup said budget.
- Channel Hop: RKO distributed the film in theaters, but in 1958 producer Howard Hughes took control of the movie with the intention of ensuring it would never be seen again outside of infrequent TV broadcasts (see below). Several years after his death, Universal purchased the film along with several of Hughes' other works, reissuing the film later that year.
- Contractual Obligation Project: John Wayne made the film to close out his contract with RKO.
- Creator Backlash: John Wayne would later shudder at the mention of the movie and claimed the moral of the story was "not to make an ass of yourself trying to play parts you're not suited for."
- Creator Killer: Not only did this movie ultimately down RKO Radio Pictures, the shooting location made this a literal trope since radiation from nearby nuclear test site ultimately killed many of the cast and crew, possibly including star John Wayne. It was also Howard Hughes' final motion picture project, ending his 30-year involvement with the film industry. Jet Pilot, a film he produced in 1949, was not released until 1957.
- Dueling Movies: With Alexander the Great, another infamous biopic about a historical figure. Neither of them were well received, although this one made more money.
- Fake Nationality:
- Keep Circulating the Tapes: A deliberate example. Howard Hughes bought all prints of the movie from RKO in order to keep the film from ever being seen again, aside from a few television airings. For two decades, the only way to watch the film was through bootlegging. Paramount Pictures tried to re-release the film in 1974, but received a cease-and-desist letter from Hughes. Only in 1979, several years after Hughes' death, did Universal acquire the film from his estate and began recirculating the film once again.
- Old Shame: Howard Hughes highly regretted producing this movie, so much that he refused to let anyone screen the movie again (see above) until several years after his death. He felt very guilty over his decision to film The Conqueror miles away from the Nevada test site where nuclear devices are tested. It is believed that the location had dangerous material in the air that led to many of the crews' deaths, including John Wayne. It is also believed that Hughes had watched this film endlessly on television during the last few years of his life (possibly due to his Super OCD).
- The Production Curse: Years after the making of this film, members of the cast and crew, were diagnosed with cancers and leukemia. Until somebody pointed it out, the common link to the film was never realized. It turned out to have been shot in the deserts of southern Utah, not far away (and more importantly, downwind) from a nuclear test site in Nevada. Even worse, they trucked the hot (radioactive) dirt from the desert back to Hollywood to finish off the sets they were building for verisimilitude. The cluster of cancers was due to having lived and worked on the film set, where the fall-out was densest... this is unique, as the cause of the "curse" - thirty years on - was so unmistakably clear, with ample evidence to back it.
- What Could Have Been: Marlon Brando and Richard Burton turned down the lead role.
Trivia / The Conqueror