Spider-Man: No Way Home has a lot of continuity nods to the Marvel Cinematic Universe as well as the other two live-action Spider-Man franchises themselves.
In General
- The order in which the villains show up for the final battle is the reverse order in which they were introduced: Electro first, then Lizard, Sandman, Octavius, and finally Goblin.
Marvel Cinematic Universe
- MJ keeps the sketches she did of Peter in detention above her bed's head frame. Zendaya's credit also includes said sketch.
- Once Peter and MJ get back to the apartment Peter changes into the "I Survived My Trip to NYC" T-shirt that he got from Tony Stark after the ferry incident where Tony confiscated his suit.
- Peter tries in vain to make a dying May stay with him by repeating, "It's just me and you." May said the same thing to Peter when she wanted him to put his cards on the table about why he had been missing classes and behaving erratically.
- Dillon takes Peter's identity in stride and mentions there must be a black Spider-Man somewhere, a nod to Miles Morales, the nephew of Aaron Davis who he briefly alluded to as a reason he didn't want Vulture's weapons being sold in his neighborhood.
- Tony's "minor upgrade" note for Peter appears in the background of executive producer Louis D'Esposito's credit.
- During Marisa Tomei's credit, one drawing in the background shows a tie being done in the Windsor Knot style, referencing the time May taught Peter how to do that before his homecoming dance.
- A text scroll during the news montage notes that a warrant has been issued for the arrest of Night Monkey, still believed to be a Czech Spider-Man copycat. The extended edition shows MJ being questioned on Night Monkey's whereabouts.
- Throughout the film, MJ wears the broken Black Dahlia necklace Peter gave to her in London.
- Peter expresses shock that The Multiverse actually exists in this film when Doctor Strange discusses it with him. Peter had previously heard about it from Quentin Beck who claimed to be from another universe, only to later realize that the man was lying his ass off after learning his true nature.
- A note detailing Peter's Grand Romantic Gesture plan for MJ appears in the background of executive producer Victoria Alonso's credit.
Other MCU Works
- The opening scene of the film sees Spider-Man and MJ swing past a billboard advertising Rogers: The Musical. This is something of a Call-Forward, since Hawkeye doesn't see the play until Christmas.
- The mural in Midtown High that has the faces of many known real life historical figures has been updated to include Howard Stark and a young Hank Pym.
- The photo of Happy used when the news is reading a statement from him is of his long-haired appearance from the prologue of Iron Man 3.
- Matt Murdock when judging Peter's case, immediately jumps to his defense knowing he's innocent, a Call-Back to his lie detecting ability. He similarly advises Happy to get a good lawyer for 'borrowing' the Stark Tech, but declines to fight his case due to the same reason.
- One of the sorcerer apprentices in the sanctum is cleaning the weird model thing that Thor knocked over when he visited the Sanctum in Thor: Ragnarok.
- The manner in which Doctor Strange casts Peter out of the Sanctum Sanctorum is eerily reminiscent of the way The Ancient One kicked Steven himself out of Kamar-Taj in the good doctor's own film.
- Peter, once again, mistakes someone's real name for an Atrocious Alias. This time, it's Dr. Otto Octavius.
- Electro's new look shows that his power is harnessed from a mini Arc Reactor, relying on mechanics established in Iron Man 2. That film also featured a villain who, rather than using the miniature reactor as a power source, weaponized its energy output directly. When powered up, his costume closely resembles Whiplash's. The only difference being Vanko concentrated the electricity in his whips, while Electro has unleashed it in its raw form.
- Strange grimly refers to the deaths of the villains who perished fighting Spider-Man as "sacrifices" that meant more for their universe than their lives did, alluding to how he reluctantly led Tony Stark on the path to sacrificing his own life to save the universe from Thanos.
- During their fight in the Mirror Dimension, Doctor Strange sends the Cloak of Levitation after Peter and it affixes itself on his shoulders and has him wear it for a bit, much like he did in What If... Zombies?!.
- Strange reveals that he has been "dangling over the Grand Canyon for 12 hours" in a very similar manner to a disgruntled Loki in Thor: Ragnarok who was "falling for 30 minutes" after being dropped through a portal by Strange himself.
- When Peter-2 notes how he fought Venom in his universe, Peter-1 reveals that he also fought an alien, although he has the extra bragging right of having fought him both on and off-world.
Spider-Man Trilogy
- Whenever Norman is in control, his teeth are straight and normal, pulled off via dental implants, but whenever the Goblin is in control, his teeth are Willem Dafoe's natural crooked and gapped teeth, much like how they were displayed in his original appearance.
- Norman argues with the Goblin whose voice is made to seem like it's coming directly from his mask.
- After Norman sheds the Green Goblin outfit, he tries to go back to his home in the city. Eventually, he winds up at Aunt May's outreach center. He tells May and Peter that someone else is living in his place.
- When offering to help Peter send the villains home, Norman says, "You know, I'm something of a scientist myself."
- Both Octavius and Sandman mention Osborn's death being impaled by his own glider.
- In the first Spider-Man, Green Goblin attacks Aunt May after discovering Spider-Man's Secret Identity; she fortunately survives there. He repeats it here, and May's MCU counterpart isn't as lucky.
- Raimi-verse Peter assures Webb-verse Peter, who doubts that he is a good-enough hero, that he is "amazing", which the latter appreciates. Mary Jane assured Raimi-verse Peter of the same when he saved her from muggers.
- When Green Goblin swoops in during the final battle, he once again says, "Can the Spider-Man come out to play?!"
- Immediately preceding this, careful listeners can hear the shrill and sharp sound effect of Peter-2's Spider-Sense going off, just as it did in the Raimi films.
- During the final brawl between Peter and the Goblin, the Goblin slashes Peter's arm with his Blade Below the Shoulder, much like he did to his own Peter with his pumpkin bombs in the burning apartment.
- The Raimi-verse Peter once again ends up catching the Green Goblin's glider blades before it impales something. This time, he ends up stopping MCU Peter from impaling the Green Goblin.
- When Peter gains controls of Ock's arms on the bridge, Ock demands that they listen to him, much like he did at the end of that film.
- There's a shot of Norman running away while his Goblin mask is lying shattered next to a dumpster, mirroring the shot of Peter Parker tossing his Spider-Man suit in a trash can, which is itself a reference to the iconic "Spider-Man No More!" panel from The Amazing Spider-Man #50.
- Sandman recalls how Otto's death drowning in the river with his fusion reactor made headlines.
- When asked if he's ever had a Web Block, the Raimi-verse Peter did mention that he did once thanks to an existential crisis, a quick nod to the time he temporarily lost his powers and quit being Spider-Man.
- When all the Peters are reminiscing about their past, Raimi-verse Peter mentions how he had a falling out with Harry (due to the Green Goblin) and how he died to save him. He also mentions Venom, Harry's killer, as the alien he fought earlier.
- Raimi-verse Peter also offhandedly mentions that he has been stabbed before (and by an Osborn, no less).
The Amazing Spider-Man Series
- The Lizard has only four fingers on his right hand, keeping in line with how it regenerated after being blown off by Captain Stacy's shotgun.
- Once again, one of Spider-Man’s villains calls him "Poor Peter" during the final battle. No "Parker" this time though.
- During the credits, Andrew Garfield is depicted in a sketch where half his face is being covered by his distinctive mask from the first TASM movie, rather than his mask from the second (which he wears in this film).
- When Electro first materializes in the woods, he's briefly seen in his blue bioluminescent appearance from The Amazing Spider-Man 2, before absorbing energy from the new universe causes him to regain his full human body.
- Before returning to their home universes, Webb-Verse Spider-Man apologizes for his insensitivity to Max Dillon, the event which catalysed the latter's transformation into Electro.
- When Peter, Ned and MJ are discussing their futures at MIT, Peter asks if there's crime in Boston the same way Webb-verse Peter asked Gwen Stacy if there's crime in England.
- Electro arrogantly recalls as he was absorbing New York's electricity and data (which Gwen and Peter purposefully did to stop him), and then noticed he landed in the MCU, realizing he was about to die then.
- When discussing the supervillains they've fought in the past, Webb-Verse Peter complains that among the villains he faced was "a Russian guy in a rhinoceros machine", which was the final scene that capsulated the Webb duology as a whole.
