Superman is one of DC's strongest heroes, and can be a thorn in the side for any comic book or screenwriter who tackles him. That's mainly because he's super hard to defeat, so much so that ensemble features typically have to burden him with one specific task to prevent the reader to ask why he doesn't just do everything the rest of the team is working on. Superman has had his troubles in the DC Universe, though I believe he'd struggle much more with a solid number of Marvel villains.
There are some Marvel villains that would easily crush Superman in a fight. With that being said, I'm not just going to rattle off the strongest villains that would vaporize the Man of Steel on sight. Instead, I'm taking things down a few levels and presenting some options that could be defeated by Superman, but would overall be at an advantage against him. Long story short, don't expect Onslaught or Franklin Richards, but this list may have some touches of cosmic strength as one works their way down.
As demonstrated in Dark Phoenix, the Phoenix force is among the strongest entities in the X-Men universe. Through Jean Grey, it allows for psychic and telekinetic abilities that are off the charts in terms of strength. The only real way to defeat Dark Phoenix is to get through to the real Jean, who Superman doesn't know.
And while Superman may be one of the strongest beings in DC Comics, his mind isn't immune to the effects of telepaths. This Marvel villain would be able to dominate the mind of Superman with little to no effort, and he'd be bent to her will and ultimately defeated in whatever way she chose from there. As long as Dark Phoenix didn't try to make Supes a puppet to do her bidding and buy him time for the real Jean to intervene, I'd say this battle would come to an end rather easily.
Doctor Doom isn't just one of the greatest Marvel villains ever conceived, he's also a formidable foe for nearly any hero. This includes Superman, who could easily overpower Doom when it comes to brute strength, but is outmatched when it comes to matters of the mind. Doom would certainly find a way to create or find kryptonite to weaken the hero, and drastically lower the gap of strength between them.
Beyond being intellectually superior, Doctor Doom is one of the more magically proficient Marvel villains out there. Superman is invulnerable to many things, but magic is notoriously one of the things he struggles a great deal with. Provided Doom could prevent the physical power of Superman, he could easily subdue him with plenty of magic and some advance planning. If the two were to just meet on the street randomly, however, it'd really come down to how Doom learned Supes' weakness, and if he could exploit it before Superman took a shot.
The god of mischief Loki may not be a physical threat to Superman in any way, but he does have the standard durability of an Asgardian. That alone allowed him to take a thrashing from Hulk in The Avengers, and while it didn't look like it tickled, it was shown he walked away from the encounter in Avengers: Endgame with seemingly little to no long term damage. That's impressive, not to mention a little intimidating.
Much like Doctor Doom, Loki is one of the notable powerful magic users of the Marvel universe. His command of magic combined with his ability to keep Superman adequately confused with his vast array of tricks, I don't see any scenario where Superman would easily defeat Loki on his own. With the full power of the Justice League he may get it done faster than The Avengers did, but that's not what this list is about.
The MCU has come a long way in elevating the quality of superhero movies, but even now, there are some things that can only be done in the comics. Case in point, we have Venomsaurus Rex, who was first conceived during the Old Man Logan comic run. This is essentially a Tyrannosaurus Rex from the Savage Lands that had eaten a symbiote chasing Logan and Clint Barton. It's still a T-Rex, though everything about it is enhanced due to it also being inhabited by the Venom symbiote.
The Marvel villain would be one tough nut to crack for Superman, for various reasons. To start, it's a freaking dinosaur, and while it can't throw a punch, that symbiote ability will allow it to do a bunch of things a typical dinosaur couldn't. Also, let's not forget the symbiote itself would see a superior foe in Superman, and try to attach itself accordingly. Even if the T-Rex itself was killed, I'd have to think the symbiote attaching to Superman and corrupting him would be a definitive win for Marvel villains everywhere.
I'll be the first to admit this is a dicey option. Again though, I'm looking for villains that would give Superman a run for his money, not necessarily Marvel villains that would demolish him immediately. Even still, the iconic Spider-Man villain Electro is a long shot, but under the right circumstances he could take Superman to the limit, and maybe even defeat him in a one on one battle.
While it isn't always true of the character, Superman has been shown to be sensitive to electricity. Provided this is the case in a battle with Electro, that's a trump card that the villain can go to again and again to exploit against Superman. With that said, even Superman is frequently shown to overcome insurmountable odds, so I could definitely see him overcoming Electro through some planning eventually. Electro would have to strike fast and keep the pressure on, and if he did that, I think he'd pull out the win.
With the power of Cyttorak flowing through him, Juggernaut is a powerhouse. His strength is limitless, he's physically invulnerable, and nigh-impossible to stop physically when he gains momentum. He's one of the stronger people in the Marvel universe, but still below as powerful as the Marvel strength chart can go. Not counting Gods though, it took Hulk being enhanced as a Horseman of Apocalypse with Celestial technology to physically stop Juggernaut in motion. In layman's terms, it took a hell of a lot power to make that happen.
Superman would not be able to physically stop Juggernaut without some modifications of his own. Even though, the mystical power of Cyttorak is a form of magical ability, which would feasibly mean that merely getting struck by Juggernaut would injure Superman greatly. The best Superman could hope for is to outsmart or fool Juggernaut into some trap, though I don't see a situation where the Man of Steel could effectively overcome this Marvel villain.
Got any other picks for Marvel villains that would be Superman? All suggestions can be thrown down in the comments. Be sure to stick with CinemaBlend for more Marvel news, and for more updates in general on what's happening in movies and television.