- Acting in the Dark: During filming, Seamus Davey-Fitzpatrick was never told that his character was supposed to be the son of the Devil. Julia Stiles has commented that it was because the filmmakers thought "he was too young to understand it, but he was really obedient when John asked him for the Damien face."
- Billing Displacement: Stiles receives top billing for her portrayal as Katherine and the character herself is the center of the trailers. In the film itself, she fills in as the protagonist's Satellite Love Interest and gets killed rather suddenly near the end of the film's second act. Meanwhile, David Thewlis, portraying the protagonist's main sidekick, is credited fourth.
- California Doubling: Prague and Dublin doubled for London. The "Jerusalem" scenes were filmed in Matera, Italy.
- Meaningful Release Date: The remake was released on June 6, 2006.
- No Stunt Double: Julia Stiles did her own stunt when she fell to the floor (when Damien tries to kill his mother). The flooring for that scene was specially built and padded so that she could safely do the fall.
- Refitted for Sequel:
- In the original film, Mrs. Baylock was initially written as a warm old lady, but it was changed to a cold hag shortly before Billie Whitelaw was cast. Mia Farrow's take on the character resembles its first characterization.
- The death of Mrs. Baylock by having Robert hit her with his car was originally scripted and filmed in the original, but scrapped for being excessive.
- Throw It In!: Mia Farrow's death kiss to Julia Stiles wasn't scripted and no one knew she was going to do it, but it was left for being adequately creepy.
- What Could Have Been:
- Pierce Brosnan and Jim Carrey were both considered for the role of Robert Thorn.
- The role of Katherine Thorn was originally offered to Rachel Weisz, who declined because she was pregnant at the time. Other actresses considered for the part were Laura Linney and Alicia Witt before Julia Stiles got the part.
Trivia / The Omen (2006)