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!"
Most of the Illuminati council scene was filmed separately with the different actors as they weren't really together.
Elizabeth Olsen flew to London to work on this film just two days after she finished filming WandaVision (2021).