Captain America is one of Marvel's greatest heroes and there are few out there who would say otherwise. He's been inspiring others for generations, setting an example of heroism that extends back to World War II. Over the years, he's faced down all manner of threats both on his own and with the Avengers, proving that his skills are useful no matter the day and age.
While Captain America is known for winning, he doesn't always do so. In fact, there are plenty of foes he's fought over the years who have always defeated him, whether on his own or with teams.
8 Magneto Beats Cap All The Time
Magneto is easily one of the most powerful people on Earth. His control over magnetism means that if he so decides, human civilization is over. He can tear apart buildings' metal skeletons with a thought, let off electromagnetic pulses that completely decimate power grids, and stop the blood flowing in everyone's veins around him because of its iron content. He's beaten the Avengers singlehandedly many times.
Cap has a metal shield and wears chain mail, so he's extremely susceptible to Magneto's attacks. In battles against the magnetic mutant, he's basically a non-factor. He can't mount an effective offense and Magneto usually just brushes right past Captain America as if he's nothing, because to someone of Magneto's power, he is.
7 Hyperion Is One Of The Most Powerful Beings In The Marvel Multiverse
Hyperion has made appearances across the Marvel Multiverse as a member of the Squadron Supreme and on his own. As an Eternal, he's extremely powerful and some versions of him—most infamously the one known as King Hyperion—have killed every hero on their Earth, including Captain America. While Captain America has helped fight against versions of Hyperion that have visited the 616 universe, it's another fight where he's pretty much useless.
Hyperion is just much too powerful for Cap to affect and the Sentinel of Liberty knows better than to deal with Hyperion on his own. He leaves Hyperion to Avengers like Thor, people who are more on his level. The Avengers may have beaten Hyperion and his Squadron, but Cap has never been a lot of help against the man himself.
6 The Hulk Is Too Much For Captain America
Hulk has changed a lot over the years but one thing that hasn't changed is his ability to smack around the Avengers. It's the same basic thing every time they fight: Hulk is mad, the Avengers just make him madder, and he beats them up until he feels like stopping. Cap has been there for a lot of these fights and in every one, he takes some of the worst beatings. Cap isn't about to let his friends get put in danger but he's also next to useless against the Hulk.
Beyond using his shield to defend other Avengers, Cap's utility in a fight against the Hulk is trying not to get one-shotted and giving orders that will help the team last longer against the Hulk. He's never won a solo fight against the Hulk either.
5 The Sentry & The Void Are Too Powerful For Any One Hero
The Sentry is one of Marvel's most powerful heroes and his dark side, the Void, is even stronger, unencumbered by Sentry's morality. Gifted with the power of a million exploding suns, the Sentry and Cap were Avengers teammates, with the Sentry being called in only when things were at their worst. Cap's death stopped him from battling against the Sentry while he was a member of Iron Man's Mighty Avengers, but his return at the tail end of Norman Osborn's Dark Reign saw Cap fighting him as the Void.
While Cap was able to help out when empowered by the Norn Stones, the Void quickly overcame him and the other Avengers. Cap was again made into a non-factor in the fight, but Thor was able to take the Void down. Since then, Cap has tried to fight against the Sentry but it was futile.
4 Daredevil Beats Everyone Somehow
Daredevil isn't someone who one would believe has beaten Captain America, but he has. Daredevil has been in a lot of amazing fights and he's defeated foes that no one thought he'd be able to: Spider-Man, Wolverine, Ultron, Beast, Hercules, and so many more. Cap is a part of that number, as Daredevil's radar senses and fighting skills have proven too much for the Star-Spangled Avenger.
Daredevil is one of Marvel's most paradoxically tough heroes. He's lost to guys like the Punisher, yet somehow beats people like Ultron and Mr. Hyde all the time. The fact that he's beaten Cap is one of his more impressive feats, showing just how great he is.
3 The Celestials Are Nearly Unbeatable
The Celestials are some of the most powerful and intelligent beings in the Marvel Universe. While the Avengers have recently proven able to defeat a Celestial, it wasn't because of Cap. Like any other human, he is so dwarfed by the power of a Celestial that his usefulness in the battle was more as a support role. Before defeating this Celestial, the Avengers had never beaten one before.
The fact the team was able to beat one at all is impressive but it was a diseased Celestial that wasn't anywhere near full power. Cap's planning and example helped but he wasn't exactly very useful in the battle against it. That's been a hallmark of every one of his confrontations with a Celestial.
2 The Avengers Have Beaten Ultron, But Cap Wasn't A Lot Of Help
Ultron is one of the Avengers' greatest foes and his destructive rampages have been stopped by the team every time. Cap has been a part of those battles, but his part was mostly as the team leader. Anytime he tried to fight Ultron on his own, he was quickly dispatched by the android. He could defend himself against Ultron's attacks but his offense bounced right off the mad automaton, as his adamantium shell was impenetrable to Cap's shield.
While Cap never backed down from Ultron, he's never been able to hurt him. Ultron is usually beaten by the more cerebral members of the team, with Cap usually acting as a distraction or directing the battle from afar.
1 Thanos Has Very Few Defeats From Any Of Earth's Heroes
Thanos is one of Marvel's greatest villains. A powerful and intelligent foe, Thanos has defeated just about every foe he's come across at least once, and very few of Earth's heroes have ever been able to defeat him. Whether he has the Infinity Gauntlet, a Cosmic Cube, or just his own powers, Thanos has proven more than a match for most of his foes, including Captain America.
While Cap has never beaten Thanos, he does have one of the more impressive losses against the Mad Titan. He walked slowly towards the Infinity Gauntlet-wielding Thanos and locked eyes with him, knowing the whole thing was futile. He got a punch off before Thanos killed him with a casual backhand. It was a loss but it was still amazing.