- Absentee Actor: Iris, Donavan and Will don't appear in "Devil's Night".
- Acting for Two: Finn Wittrock plays both Tristan Duffy and Rudolph Valentino, Sarah Paulson plays both Sally and Billie Dean Howard and Lily Rabe plays both Aileen Wuornos and a photograph of Nora Montgomery.
- Advertised Extra: Minor case with Lady Gaga as The Countess. Her character is definitely central to the setting, but doesn't get nearly as much screen time as many of the regulars. In the flashy pre-season promotional material she's practically omnipresent.
- Fan Nickname: Agnetha and Vendela have "the Swedish meatballs."
- Missing Trailer Scene: None of the clips from the preview of episode 8 are seen in the actual episode. Justified because said episode is one big reveal that Lowe is the Ten Commandments Killer.
- Throw It In!: In the pilot, Lady Gaga completely improvised the line, "Your boy has a jawline for days." Matt Bomer was so amused by the line that he almost corpsed (no pun intended).
- What Could Have Been: A couple of actors, and possibly their intended characters, never made it in to the series despite early reports.
- Emma Roberts (who'd previously starred in Coven and Freak Show) was originally confirmed as having been given a one- or two-episode guest spot near the end of the season, once she'd finished filming as the lead in the first season of the show's spiritual spin-off Scream Queens (2015). However, for whatever reason her character was cut, though whether it was due to the episode order being reduced by one, or other reasons, has not yet been stated.
- Ryan Murphy claimed to have written a "perfect" role for Jessica Lange, star of the show's first four seasons, if she would agree to return for the fifth. However, though Lange was apparently very interested in the character, she ultimately stuck to her decision to leave the show; it's not known whether her character was given to someone else or written out.
- According to IMDb, Evan Peters was originally supposed to play Tristan. If that's true, it explains why Finn Wittrock played two new, unrelated characters in a single season; Rudolph Valentino would have originally been his only role, and a different actor entirely would have played March.
Trivia / American Horror Story: Hotel