Warning: SPOILERS for Spider-Man: No Way Home
Spider-Man: No Way Home brought Peter Parker in conflict with villains from past franchises, pulling in one villain from each of the movies before Tom Holland took on the role. This also meant that Spider-Man in the Marvel Cinematic Universe was fighting some of the most intelligent villains in the character's film history.
By the end of the movie, it was the intelligence of the characters that played into the final outcome of the movie, an ending that was perfect for the hero. With so many brilliant characters in the movie, be they good or evil, the most intelligent characters in Spider-Man: No Way Home rank among the brightest in the entire MCU.
Sandman
Out of all the villains in Spider-Man: No Way Home, the least intelligent of them was Flint Marko, also known as Sandman. While the other villains had history in the scientific community, Flint was just a common street criminal before becoming Sandman.
By the time he arrived in Spider-Man: No Way Home, Flint was fighting on the side of good, but thanks to the confusion of the multiverse, he proved he was still the common street thug fighting for his survival favoring his instincts over his brain.
Aunt May Parker
Aunt May Parker was smart, but she was nowhere near the intelligence level of other characters in the movie. Instead of relying on a high intelligence, she relied on her inherent goodness and kindness to make the right decisions.
May ran a shelter that helped the homeless, and she knew what she needed to tell Peter in order for him to make the right decisions in his life. While Peter is one of the smartest characters in the MCU, Aunt May was always his moral com.
Happy Hogan
Happy Hogan was never the smartest guy in the room, but he was always someone who was there for his friends when they needed him the most. Iron Man was brilliant, but Happy was mostly pure muscle as his head of security. As a Spider-Man ing character, he was a sounding board who was there to point Peter Parker in the right direction.
Happy was smart, but not on the level of those he interacted with in the hero community. He did prove a level of intelligence when he actually stole Stark Tech before the government could confiscate it.
MJ
MJ and Ned Leeds were high-school students up until Spider-Man: No Way Home, and while they were not on Peter Parker's level, they were still both smart enough for consideration at MIT. However, out of the three friends, MJ was just a step below them.
MJ was smart, but she never showed any propensity in the films for science, inventions, or anything other than her sense of humor. She was hinted at as being very smart, but not on the level of Ned.
Ned Leeds
Ned Leeds was always showing how smart he was throughout the three Spider-Man movies. He was Peter's "man in the chair" and he was the guy who could pull out the computer and find anything that Spider-Man needed.
Ned proved he was the tech wizard of the two and he always was able to get Spider-Man where he was supposed to be to stop the bad guys. He did it again in Spider-Man: No Way Home and his computer skills alone showed more intelligence that the movie allowed MJ to display.
Electro
A lot of people forget that Electro might not have looked intelligent in The Amazing Spider-Man 2, but he was a scientist just like those around him. The only problem was that he was insecure and considered himself a nobody.
It was Max Dillon who created the process that Os-Corp stole from him and ended up turning him into Electro. Electro is a lot smarter than people give him credit for, and showed it again in Spider-Man: No Way Home. but he still couldn't match up to the big brains of the villains from the multiverse.
Dr. Strange
Dr. Strange is one of the smarter characters in the MCU, a brilliant surgeon turned the Sorcerer Supreme, at least until the blip caused him to lose that role. Despite that, he is still a brilliant sorcerer, but he showed his limitations in Spider-Man: No Way Home.
Dr. Strange is smart enough to come up with ideas to fix things, and he showed in the Avengers movies that he could transition on the fly, but he also showed a quick temperament in this movie and often needed pushed in the right direction to make the smartest choice, especially concerning Spider-Man's villains.
Doctor Octopus
Doctor Octopus was a brilliant scientist in Spider-Man 2 and he created ways to help the world, and a way to destroy it. However, he had the same problem that Norman Osborn had in the movies. He lost control of himself and his intelligence suffered for it somewhat.
However, Octopus was always close to being a hero in the movies, and he proved that again in Spider-Man: No Way Home and was intelligent enough to prove himself once again, although he always failed to quite reach the level of Norman Osborn.
Green Goblin
Norman Osborn is one of the smartest people in the Marvel Universe and he carried that brilliance over to Sam Raimi's Spider-Man movies. He proved it once again in Spider-Man: No Way Home. Norman was the man who helped Peter not only find a way to cure Doctor Octopus of his insanity, but also helped find a way to fix Electro.
However, Norman lost his grip on reality, and when he was not in control of his own brain, the Green Goblin took over and lowered his intelligence in exchange for pure rage. However, when Norman was in control, there was no one more intelligent in Spider-Man: No Way Home.
Peter Parker/Spider-Man
The most intelligent character in Spider-Man: No Way Home is complicated. When it comes to pure education and scientific knowledge, no one really touches Doctor Octopus and Norman Osborn. However, this movie put Spider-Man on a level by himself.
This is because there were three Spider-Men in the movie, and each of them carried their own levels of brilliance. Together, the three Spider-Men created cures for all the villains and then came up with a plan to fix the problems before saying goodbye. It was Peter Parker and not Dr. Strange or any of the villains, who figured out how to save the world, and that makes him the most intelligent character in Spider-Man: No Way Home.
