- Billing Displacement: Although Donald Sutherland has top billing in the credits and posters, he doesn't appear until roughly 40 minutes into the film. Similarly, the prominently billed Burgess Meredith only appears in the first half of the movie.
- Cast the Expert: Shows up in the film version; who better to cast as the director of the film within a film than an actual veteran film director? And so the director of the Napoleonic drama on which Tod is employed as a set designer is played by veteran B-movie director William Castle in his last onscreen role.
- Dawson Casting:
- Name's the Same: Homer Simpson, the Iowa accountant, happens to share his name with one of the most famous cartoon characters of the Nineties, Noughties, and New Tens. As Matt Groening allegedly named the parents in The Simpsons after his own parents, Homer and Margaret Groening, the identical names are probably just a coincidence, although he stated in interviews shortly after The Simpsons premiered as a standalone series that he chose the name as a tribute to The Day of the Locust. Groening may be the only person who knows the truth. The Simpsons itself had a gag where, after dealing with a swarm of grasshoppers, Homer said "I never thought Homer Simpson would be a part of the Day of the Locust."
- What Could Have Been:
- Peter Bogdanovich was offered the chance to direct.
- Malcolm McDowell was offered the role of Tod Hackett, but turned it down, feeling it was too similar to his Mick Travis character from If... and O Lucky Man. Dustin Hoffman was briefly attached.
- Jane Fonda, Goldie Hawn, and Jill Clayburgh all turned down the role of Faye Greener. Sally Struthers was approached for the part, but couldn't get out of her taping commitments for All in the Family.
- James Cagney turned down the role of Harry Greener.
- Write What You Know: Nathanael West had been working as a screenwriter for Columbia Pictures for several years when he wrote The Day of the Locust, and many of the characters and settings in the novel are based on his experiences living in a hotel on Hollywood Boulevard, while the abortive sexual encounter between Homer Simpson and Romola Martin in Chapter 8 is based on a similar experience West had when working as a night manager in a Manhattan hotel in the early 1930s.
Trivia / The Day of the Locust