(at around 1h 3 mins) When Strange meets Reed Richards he says "The Fantastic Four, didn't you chart in the 60s?". A group called The Fantastic Four had a #6 R&B hit in 1967 with "The Whole World Is A Stage". This is also a call back to the first movie, Doctor Strange (2016), where he answered music trivia questions in the operating room.
(at around 52 mins) In the living room of Wanda-838, the TV shows a cartoon featuring Oswald the Lucky Rabbit. Walt Disney invented the character in the 1920s, but when Universal Pictures took the rights to Oswald away from him, Disney invented Mickey Mouse instead, who soon completely eclipsed Oswald in popularity. In Earth-838 it appears that Mickey Mouse was never invented, and so Oswald remained popular on TV.
Benedict Cumberbatch revealed in an interview that Benedict Wong broke about four ribs when he slammed into something during a stunt.
Sam Raimi initially didn't want to direct any future superhero films, having lost faith in himself due to the critical and audience backlash he received from Spider-Man 3 (2007) due to studio interference from Sony. However, getting the call from his agent about this film encouraged him to try again, as he had thoroughly enjoyed the first Doctor Strange film (as well as the character himself) and wanted to see if he could live up to the challenge of meeting the audience's expectations once again.
Director Sam Raimi previously added two references to the character Doctor Strange in Spider-Man 2 (2004):
- Joe's Pizza (where Peter Parker is working at the beginning) and the billboard showing Mary Jane are located on Bleecker Street (where Doctor Strange's Sanctum Santorum is located).
- The name of Doctor Strange is suggested to J. Jonah Jameson as a possible name for Dr. Octavius, to which Jameson replies: "But it's taken!"
Michael Waldron: The film's writer plays Charlie's best man at the wedding. He appears on the balcony next to Christine.
Scott Spiegel: As the voice of one of the Souls of the Damned. Spiegel has been friends with Sam Raimi since high school, and they have collaborated on numerous films.
Sam Raimi: [Campbell] (at around 41 mins) Pizza Poppa is played to comic effect by Bruce Campbell. Raimi and Campbell have been friends since high school, and Campbell has appeared in nearly all of Raimi's films, including all three Spider-Man films.