Mr.Fantastic is another polymath—he's a master of a wide variety of scientific disciplines: rocket science, biology, physics, extraterrestrial studies, and so much more. Iron Man is known for being arrogant but even he would admit that Mr. Fantastic is way smarter than he is.
Galactus was already smarter than Iron Man before he became Galactus, but in the ensuing billions of years, he's only gotten smarter. He's even been able to tap into the cosmic consciousness, which allows him to see events anywhere in space and time. Galactus's intelligence dwarfs Iron Man's.
Hulk and Banner are two distinct entities. Banner remaining inside of Hulk doesn't change Hulk's IQ. Which Hulk? If we're talking Savage Hulk, I'd put his IQ right around 99 on the Current “Wechsler IQ Classification” scale.
Apart from his physical abilities, Peter is an intellectually-gifted scientific teen genius and has a prodigious aptitude in the physical sciences, with a high IQ level of around 250.
Rocket famously said that Tony Stark was only smart for Earth, and he's proven time and time again that he's the smartest character in the MCU. He can think his way out of almost every problem, create a gadget out of basically anything, and is now the official leader of the Guardians of the Galaxy.
Although he is an extremely skilled marksman, Clint Barton is often considered to be the weakest member of the team seeing as he's just a regular guy with a bow and arrow.
It's not too surprising that Doctor Doom is Tony's intellectual better. With the reveal that Tony's gift actually made Reed Richards dumber, it makes sense that Mister Fantastic nemesis would be in a similar league and have an edge on even the Iron God when it comes to genius.
Strength. Captain America is physically stronger than Iron Man, whether with his suit or not. If they both entered a ring-to-box hand-to-hand combat, Captain America would destroy Iron Man in that fight.
Tony Stark is the wealthy son of industrialist and weapons manufacturer Howard Stark and his wife, Maria. Tony grew up a genius with a brilliant mind for technology and inventions and, naturally, followed in his father's footsteps, inheriting Stark Industries upon his parents' untimely death.
As mentioned earlier, Elon Musk's IQ score is believed to be between 155 and 160. Above-average IQ scores within this range are only reserved for the "Highly Gifted" IQ classification.
Genius Level Intellect: Batman is noted as having an I.Q. of 1045. Investigation. Marksmanship. Martial Arts: Batman is a master of martial arts from across the universe, able to catch the original Batman off-guard and defeat him with a single blow; he is also known to incorporate psychic attacks into his fighting ...
In a world filled with super-genius heroes and villains, Tony Stark and Reed Richards are among the smartest people in the universe. Iron Man has proven to be a brilliant scientist whose on-the-fly thinking and technology have helped the Avengers more times than can be counted.
There are some that might suggest Thor is not the smartest hero in the MCU. It's true that he can rely on his muscles more than his mind in most cases, but that doesn't mean he doesn't have some very intelligent moments. In fact, sometimes he outsmarts everyone around him.
"Captain America represents the pinnacle of human physical perfection. Captain America has a very high intelligence as well as agility, strength, speed, endurance, and reaction time superior to any Olympic athlete who ever competed." Note first, he's at the pinnacle of human _physical_ perfection.
Thor Odinson himself said he is around 1500 years old at the time of the events of Infinity War (2018), and MCU fandom wiki mentions Loki's year of birth as 965 AD, hence he would be 1055 years old at the time of his death in 2018. So, Thor is around 445 years older than Loki.
Genius-Level Intellect: Even in his youth, Thanos was deemed a genius among his kind, despite his deformation. His long life allowed Thanos to refine his intellectual aptitude to the highest degree, making him exceptionally intelligent.
The Hulk, on the other hand, is often seen as a stupid, savage brute with a very limited vocabulary. While there have been versions of the Hulk with Banner's intelligence, most people still stereotype the Hulk as a big, dumb, green monster. Surprisingly, however, this is not true.
