Trivia: The Sator Square dates back to Pompeii and is a square of 5 Latin words making a palindrome: Sator, Arepo, Tenet, Opera, and Rotas. Whichever orientation the square is in the words line up in both directions. Each word features in the film - Kenneth Branagh's character is named Sator, the forger mentioned near the start is Arepo, the title is of course Tenet, the opening sequence takes place in an Opera, and the Ukranian special forces who arrive in that sequence have badges on their arms with "Rotas" on them.
Trivia: The 747 crashing into a building was shot entirely practically, with a retired jumbo jet. Christopher Nolan costed out doing it with miniatures, but realised it would be cheaper (and better) to buy the shell of an old aircraft and really crash it.
Trivia: Its release was rescheduled multiple times due to the Covid-19 pandemic. It was originally meant to be released on July 17th, and eventually ended up being released on August 26th. Warner Bros. mandated it could only be shown in cinemas where mask wearing was enforced.
Trivia: The script was kept as secret as possible, even from the stars. Robert Pattinson was only allowed to read it once before filming, in a locked room. Michael Caine was only given his specific scene to read, and has said that he had no idea what the film's plot was, despite his close links to Christopher Nolan.
Trivia: Despite many previous collaborations, Hans Zimmer turned down the chance to score this film because he was too busy working on Dune. Instead he suggested a friend of his, Ludwig Göransson.
Trivia: Christopher Nolan is a fan of the Bond films, and regularly watches them, but made a conscious effort not to watch any of them while preparing this film, despite going for a similar feeling, to best avoid any overt influences.
Trivia: Recording of the score hadn't yet begun when lockdown began due to the coronavirus outbreak. The final product had to be assembled by using orchestra members recording their parts in their own homes.
Trivia: One of the most expensive original films ever made, costing $205m.
Trivia: When the Protagonist and Neil exit the shipping container and begin running past the wreckage of the plane to get to the turnstile inside the Freeport, the ambulance that they steal later in the scene after going through the turnstile can be seen among the emergency vehicles that they run past. It is definitely the same ambulance shown on both occasions as it has the number "02-06" on top and has the same number plate "ZXI04712." The Protagonist, wearing the same armor, can also be seen sitting in the driver seat. It is not something that the camera focuses on, but it can be noticed in the background of shot. (01:40:52)