- B-Team Sequel: Richard Donner could have directed the film except he was involved in a dispute with the Salkinds over his firing from Superman II.
- Completely Different Title: In Germany and Hungary, the film was released as Barbara's Baby, a play on the title Rosemary's Baby. This title also appeared on some posters in many countries before the eventual title was announced.
- Deleted Scene: When the former ambassador looks into the mirror, he was supposed to see the face of a demonic jackal. However, the effect looked terrible so the makers decided to leave it on the cutting room floor.
- Romance on the Set: At the time of filming, Sam Neill and Lisa Harrow developed an off-camera relationship that produced son Tim Neill.
- The Shelf of Movie Languishment: The movie was filmed in 1979 but was not released until 1981.
- What Could Have Been:
- Marlon Brando, Gene Hackman, and Jack Nicholson were considered to play the grown-up Damien, until the producers went for the younger (then unknown) Sam Neill. Michael York lobbied hard for the part, but ultimately had to turn it down due to scheduling conflicts. It was this incident that later led to the creation of The Omega Code series.
- Working Title: The film's original official title was simply The Final Conflict. Later, the title was adjusted to Omen III: The Final Conflict in order to accentuate its link to the other two films in the cycle.
Trivia / Omen III: The Final Conflict