- Contractual Obligation Project: Ron Howard was obligated to do the film based on his contract for The Da Vinci Code.
- Creator Couple: Ron Howard's wife, Cheryl Howard, plays a CERN scientist.
- Fake Brit: Gunther Glick, the so-called "British" journalist, has speech and thoughts riddled with Americanisms such as "gas" and "anchormen" (a real Brit would say "petrol" and "presenters" respectively); at one point he even likens himself to Dan Rather, who is almost unknown in Britain. (Again, if he were really British he would have likened himself to Trevor McDonald, though there's a vague handwave about him hanging around American news media for too long.)
- Fake Irish: Irishman Camerlengo Patrick McKenna is played by the Scottish Ewan McGregor.
- Fake Nationality: The film has quite a dose. The Israeli Ayelet Zurer played Vittoria Vetra, who is Italian. Commander Richter and Lieutenant Chartrand, both members of the Swiss Guards, are played by the Swedish Stellan Skarsgård and the Danish Thure Lindhardt, respectively.
- One-Take Wonder: Ewan McGregor suggested to Ron Howard that he could do the sequence where the Camerlengo tells the Cardinals about the Illuminati entirely without breaking it into several segments, as he felt that he could pull it off, having known all of his lines. Howard agreed to his suggestion and proceeded to film it. The take was very good, much to the applause of everyone, that it was the only shot taken, and used in the final film.
- Real-Life Relative: Ron Howard's father Rance Howard plays a Cardinal.
- Referenced by...: Canadian figure skater Beres Clements performed to the Angels & Demons soundtrack for his long program during the 2020-2021 competitive season.
- What Could Have Been:
- Working Title: Obelisk.
Trivia / Angels & Demons