The love stories in the MCU have been a little hit-or-miss over the course of its run, but there have been many memorable love interests introduced. Sometimes these characters weren't given much to do other than provide that romantic angle to the adventure, but others shined in their own unique way.
There are a number of ways intelligence is shown through the main MCU love interests. Some never had many opportunities to show how smart they might be, others provided the much-needed voice of reason to the heroes, and some were simply brilliant people who could go toe-to-toe with the MCU's biggest geniuses.
Dane Whitman
Dane Whitman has the honor of being the first male love interest in the MCU as Sersi's human boyfriend in Eternals. Sadly, he proves to be quite useless in the role. While Dane seems to have a complex history in the MCU in the future, he likely won't be the smartest of the heroes.
While Dane doesn't come off as dumb by any means, he just sort of meanders around without any idea what to do or how to contribute to the situation. He also seems to have a tough time connecting the dots that Sersi is not a regular human, despite the many clues.
Liz Allen
Before Peter Parker and MJ became a lovable couple, Peter's first crush was Liz Allen in Spider-Man: Homecoming. Liz is a nice young woman who was obviously smart enough to lead the school decathlon team, but the movie also needs her to be a bit oblivious.
She is meant to be a typical high school girl who isn't totally aware of the world around her. When Peter and Liz's father, Adrian Toomes, are having an intense conversation as they realize each other's identities, Liz is distractedly scrolling on her phone.
Betty Ross
Betty Ross is likely the most overlooked of the MCU's love interests as she has only appeared in The Incredible Hulk. Sadly, that one appearance doesn't do the character justice beyond her being the typical love interest role.
Though she is a scientist alongside Bruce Banner, the movie never gives Betty much of an opportunity to show her intelligence. In fact, the fact that she ran into the middle of a military ambush that almost got her killed didn't make her seem all that clever at all.
Pepper Potts
As the very first love interest, going all the way back to Iron Man, Pepper Potts has cemented herself as an important part of the MCU. She is a funny, independent, and loving figure in Tony Stark's life. And while she might not stand out as a genius like some characters, she has reserved intelligence.
Pepper can seem scattered and panicky in the midst of action moments, but it is the quieter moments when she seems smarter than Tony. Not only was she smart enough to become CEO, but she also is the voice of reason Tony often needs.
Peggy Carter
Peggy is a love interest who is every bit the warrior Steve Rogers is. While she might not have the powers afforded by the super-soldier serum, she is still fearless, determined, and capable in every situation she finds herself in.
Her quick mind on the battlefield is apparent, but Peggy is also not given too many decision-making scenes in the movies. She clearly has a smart view of the world, but she impresses from her skills as a soldier.
MJ
After starting out as a funny side character in Spider-Man: Homecoming, MJ has grown into one of the most charming characters in the MCU and the most important person in Peter's life. She really comes into her own in Spider-Man: No Way Home, providing that stable emotional support Peter needs.
Like Liz, MJ is shown to be an intelligent student and she also handles high-stakes scenarios with a level head. While the movies don't give her moments of her intelligence saving the day, it is clear how clever she is by how she handles herself.
Hope Van Dyne
Though she is now a superhero in her own right, Hope van Dyne was oddly relegated to an underdeveloped love interest role in Ant-Man. It becomes even more strange when she proves herself to be a much more competent hero than Scott Lang.
Hope shows that she already knows how to be Ant-Man better than anyone but is stuck teaching Scott how to fit the role. Even in a less central role, she still comes up with much of the plan and shows how intelligent of a hero she is capable of being.
Nakia
Nakia is another very independent character who happens to be in a romance with T'Challa in Black Panther. She is another skilled warrior who could be a hero herself, but she also proves to have a more open-minded view of the world than the rest of Wakanda.
She understands that Wakanda could be helping the world in some wonderful ways instead of hiding from everyone. This is a lesson she is able to gradually teach T'Challa over the course of the movie.
Christine Palmer
Stephen Strange is a world-class surgeon who later becomes a powerful sorcerer. But as impressive as that is, Christine Palmer still has to be the one to guide him through his many bad decisions.
She is a brilliant doctor in her own right even if Stephen doesn't exactly give her the credit that he gives himself. But she is also a more rational and practical person, providing Stephen with the kind of advice he needs in his darkest times but is too stubborn to listen to.
Jane Foster
Thor and Jane Foster always seemed like a very odd couple in the MCU. Despite Thor's incredible power, he's not exactly the smartest Avenger whereas Jane is not particularly powerful (at least, not yet) but is one of the most intelligent characters in the MCU.
It makes sense that their connection is mostly brought about through Jane's various research experiments. She has a talent for discovering things that have stayed hidden from the world for centuries, like the Bifrost and the Alignment. It will be interesting to see her combine that intelligence with incredible power in Thor: Love and Thunder.