Home of collected oddities and other worldly technology, Superman's Fortress of Solitude has been a staple of comic book lore for decades. As a base of operations, it's proven to be a popular location in all sorts of Superman media, showing up in cartoons and movies alike. It's also been known to have lousy security, since it's been broken into many different times by many different villains. Whether it's in an alternate reality or a recent grim reboot, the Fortress in all its forms is no stranger to intruders.
Due to the many ways Superman has been interpreted and adapted, this list will go beyond the comic pages to include villains who have appeared in movies, television, and video games. The interactions the villains have within the Fortress must, at minimum, have a sort of malice or trickery behind them. The list also includes characters who may not always be a villain or weren't at first, but have since become a staple of Superman's rogues gallery.
Keep your large key handy, because these are 15 Villains Who Have Broken Into The Fortress Of Solitude.
Easily one of Superman's deadliest foes, Doomsday was a Kryptonian experiment that had been banished to Earth, only to eventually break captivity and wreak havoc. His first appearance was in the seminal story arc "The Death of Superman," where he and Supes battled to the death, ushering in a short-lived era where the Man of Steel was no more.
Since then, Doomsday has shown up in various other stories, including the most recent Batman v Superman: Dawn of Justice, where Lex Luthor entered the remains of the Fortress of Solitude (well, sort of; more on that later) and made Doomsday with Kryptonian DNA and tech. He's also appeared in the fighting game Injustice: Gods Among Us, where, in his own ending, he defeats Superman, traps him into the Phantom Zone, and uses the Fortress' technology to terraform the Earth into Krypton.
The "reverse" mirror image of Superman, Bizarro was originally created with a duplicating ray that resulted in an extremely imperfect replication. Featuring grotesque skin and strange speech patterns, Bizarro has often been portrayed as similarly powerful to Supes, but also as his polar opposite in terms of brain capacity. He's been known to do things incorrectly and clashing with Superman as a result.
In Post-Crisis continuity (and in Superman: The Animated Series), Bizarro was created by Lex Luthor in an attempt to make his own Man of Steel. This, of course, results in the imperfect clone that manages to retain certain memories of Supes, as well as his dangerously unchecked strength and abilities. Bizarro also makes an appearance on Smallville; this version has no body until he uses Clark Kent's DNA to take his form, allowing him access into the Fortress of Solitude and giving him super strength. However, unlike the real Clark, Bizarro's skin disfigures when exposed to intense sunlight.
13 Mister Mxyzptlk
One of Superman's most interesting and out there villains, Mister Mxyzptlk (or Mxy, as he's affectionately called) comes from the Fifth Dimension and is able to appear anywhere and, well, be anything. He makes for one of Supes' more unique foes due to his abilities, but also because of his goals and ambitions. While nearly ever other villain is out to kill Superman, Mxy mostly just wants to outwit him, which he takes very seriously, since he's been known to bother the Man of Steel anywhere and everywhere. His opponents must in fact trick him into saying his name backwards, thereby sending Mxy back to his dimension; it's the only reliable way to best him.
One of his most famous depictions came in Superman: The Animated Series, where he was voiced by the one and only Gilbert Gottfried. In his first appearance, his sole goal is to outwit Superman to say his name backwards, but as is always the case, things go too far for Mxy. In his second appearance, after Mxy vows not to bother Supes, he enlists the help of Bizarro to bother the Man of Steel for him, which of course, doesn't end well for the fifth dimensional prankster.
12 Cyborg Superman
While he might appear to be what his literal name implies, there's more to Cyborg Superman than meets the eye. The most well known version of this character is Hank Henshaw, who went to space along with two friends and his wife Terri. There, they encountered a strange radiation that immediately affected his two friends, but didn't affect Henshaw or Terri until later on. This radiation caused skin and body deterioration to such an extreme that it resulted in the deaths of the two friends and nearly his own wife.
Henshaw is able to pass his consciousness into a robot body, and with this new form, he spends time in outer space and begins to form a vengeful grudge against Superman, whom he believes is the cause for his misfortune. After learning of his death at the hands of Doomsday, Henshaw uses the Kryptonian Birthing Matrix to create a new body identical to Superman's, thus giving birth to Cyborg Superman. Recently, he's been seen on Supergirl, where he made his way into the Fortress of Solitude at the end of the Season Two episode "The Darkest Place."
11 Black Zero
Black Zero has appeared as different characters and organizations, but probably the most well known incarnation is Superboy's. Existing in an alternate reality where Superman never returned from his death (in "The Death of Superman"), this version of Superboy was genetically created to be the new Man of Tomorrow. However, after incidents involving the deaths of hundreds of civilians, the genetic project and organization that made him shut down, and massive anti-clone sentiment forced Superboy to retreat to the original Superman's Fortress of Solitude.
At the Fortress, Superboy learned about the Black Zero clone liberation movement that existed on Krypton. He took on the new name of Black Zero and made it his duty to defend all clones and stop anti-clone sentiment by any means necessary. He later created a clone army and waged war that resulted in the death of Earth's heroes, which then led him to discover and explore new realities in need of "rescuing."
Dominus was an alien priest originally named Tuoni, who had fallen in love with his peer, Ahti, who later ascended him in stature to the mantle of Kismet. Out of jealousy, he used forbidden magic to become more powerful to challenge her, but he failed. The magic had caused his body to incinerate, and in this frail state, he was sent to the Phantom Zone. It was here he encountered the holographic remains of one of Superman's ancestors, Kem-L, who helped rebuild him into a cosmic phantasm.
Reborn, Dominus escaped the Phantom Zone by way of the Fortress of Solitude, and went after Kismet. It was around this time he met Superman, whom he mind controlled and convinced into taking over Earth. Superman managed to break free from this spell with the help of Torquasm-Vo, an old Kryptonian (mental) martial art, and after a battle of the minds and fists, Superman banished Dominus back into the Phantom Zone.
Unconventional as it may seem, Starro is at once innocuous and deadly, as seen in the two-part Batman Beyond episode "The Call." Having been picked up by Superman during a battle with the Collector, it was the last of its kind and was kept safe in the Fortress of Solitude. Unbeknownst to Supes, however, Starro was devising a plan, one that would take decades to realize. During a routine feeding, it latched onto our hero's face and took control of his mind. From here, Starro bred thousands of creatures like itself, with world domination being the ultimate goal.
Using the power of Superman, Starro attempted to dismantle the Justice League; he later retreated to the Fortress, where the rest of the League discovered that Starro was behind his actions all along. However, Starro's clones began to latch onto the other members, leaving Batman as the only one left to save the day. Batman managed to trick Starro into getting electrocuted, causing it lose its influence and bring everyone back to normal. Starro, along with its clones, was then sent back to their home planet.
8 Lionel Luthor
Like son like father, there are few mere mortals as dangerous and corrupt as Lionel Luthor. Played by the ever so charismatic John Glover on Smallville, Lionel was the Luthor Corps' CEO and manipulative father of the clearly scarred Lex Luthor. After Clark Kent saved him from drowning in the premiere episode, Lex felt he owed him a debt, and the two became friends. Eventually, Clark met Lionel, who became convinced Clark that was more than he seemed. Even after Lex himself had abandoned the idea of trying to decipher Clark, Lionel was obsessed, and knew there was something there. Lionel eventually became a vessel for the famous Krpytonian Jor-El, which gave him access to the Fortress of Solitude, as well as superpowers on par with Clark's.
Alternatively, Lionel served as the father of Clark Luthor on Earth-2, after finding him in the aftermath of the meteor shower that brought him to Earth. In this reality, Clark not only learns to fully embrace his powers at an earlier age, but becomes murderous and, by extension, morally evil.
7 Lara+Quar, and the Kryptonians of Kandor
While visiting her iced and immobile father in his Fortress of Solitude, Lara (daughter of Wonder Woman) notices a distress signal from the bottled city of Kandor. Lara goes to Ray Palmer (aka The Atom) for assistance, and he uses an experimental ray to shrink them to normal size. However, this proves to have been a grave mistake; the Kryptonians have formed a cult, lead by Quar, who plan to make Earth their new home.
The plot of The Dark Knight III: The Master Race has Batman and his allies trying to put a stop to Quar before he and his cult successfully conquer the planet. Superman does his best, but is opposed by Lara, and the two of them fight for all the world to see. The fight is horribly one-sided, with Lara beating him up all the way to the Arctic. Here, Superman lays at the entrance of the Fortress, allowing Quar and his cult to judge him. They trap Superman in black matter, which renders him completely immobile, and then sink him and the Fortress into the Earth.
The product of ancient Kryptonian Kem-L, the Eradicator was a containment device that was later corrupted to have one sole mission: the preservation of Kryptonian culture by way of the eradication of all others. Hundreds of thousands of years later, Superman comes into contact with the being, which soon makes preserving the Last Son of Krypton its sole priority. It starts to have averse and dangerous effects on Earth, and Superman decides to throw it into the Antarctic; the Eradicator uses the ice to form the Fortress of Solitude, as well as posses scientists to create a portal to the Phantom Zone.
The Eradicator has shown up in various shapes and forms, including as a program in the Fortress of Solitude's computers. One of his most famous incarnations came during the "Reign of the Supermen" arc, where he assumed the role of Superman by making an organic body out of the Man of Steel's remaining solar energy. Its also during this arc that he introduces his characteristic visor, as his eyes are very sensitive to sunlight.
Mongul was once the ruler of an alien race, but a revolution left him exiled. He tried to conquer Warworld and Throneworld, but failed in later battles against Superman, fueling a thirst for revenge that culminates in the Alan Moore penned classic "For the Man Who Has Everything."
It's Superman's birthday, and all his best friends--Wonder Woman, Batman, and Robin--are coming to celebrate at his Fortress of Solitude. They find him comatose, with a strange plant on his body, and Mongul comes out of the shadows to reveal that the plant is projecting Supes' deepest desires, thus keeping him in a fantasy only true in his mind. He imagines a life on Krypton that begins idyllic but ultimately ends in turmoil.
The trio do their best to fight Mongul, and almost don't succeed. With the help of Batman (prying off the plant) and Robin (carrying it safely in Mongul's protective gauntlets), Superman is able to snap out of it to help stop Mongul. The villain himself eventually has the plant latch onto him, projecting his fantasy of superhero deaths and universal domination.
One of Superman's most deadly enemies and created by the legendary Jack Kirby, Darkseid is one of the New Gods, first introduced in the pages of DC Comics in the early 1970s. As the overlord of Apokolips, his main goal is to be the ruler of the universe, and he does everything he can to ensure heroes like Superman don't stand in his way. Apokolips had been at war with its sibling planet, New Genesis, and it established a truce by exchanging infant sons, resulting in Orion from Apokolips and Mister Miracle from New Genesis. Both of these sons have helped Superman in his various quests to stop Darkseid.
Darkseid is also the wielder of the infamous "boom tubes," teleportation devices used by citizens of Apokolips and New Genesis. These allow passengers to transport just about anywhere, and are the most common mode of transport for Darkseid and his allies. Darkseid has made many appearances in Superman media, most notably The Animated Series, where he was voiced by Michael Ironside. He's even appeared in the video game Scribblenauts: Unmasked, where he is found and must be defeated by the player in the Fortress of Solitude.
Most often depicted as a computer program with artificial intelligence, Brainiac has managed to infiltrate Superman's life in many different ways, most often due to being a piece of Kryptonian tech. Brainiac has often been portrayed as a program in the Fortress of Solitude, made to help guide and aid the Last Son of Krypton. What begins as a helpful AI later turns on its master, deciding that Earth belongs in its collection of rare (and destroyed) planets and cultures. From issues in Action Comics to The Animated Series, Brainiac has managed to fool and nearly outdo the Man of Steel several times over.
While Brainiac does not often have a body, when in full android mode, he forms his own, as is the case in The Animated Series. Other times, he's already humanoid, with green skin and strange objects on his skull. Being the keeper of Kryptonian history, Brainiac serves as a helpful and useful program for Superman in his Fortress (when he's not plotting against mankind, that is).
2 General Zod
A fellow Kryptonian, General Zod is known for having lived alongside Superman's own father, Jor-El. During this time, Zod was accused of crimes that resulted in his banishment into the Phantom Zone, where he resided until released, either by someone or by accident, depending on the storyline. Due to his warmongering nature, his appearances on Earth tend to involve him wanting to dominate it and make it a new Krypton. And since Zod is also Kryptonian, he makes for an even more dangerous adversary, usually coming very close to killing off Superman for good.
Zod has famously been portrayed by Terrance Stamp in both Superman and Superman II, where his plan to make everyone kneel before him are prevented by one Big Blue Boy Scout. Most recently, Zod was portrayed by Michael Shannon in Man of Steel, who tried to use the film's version of the Fortress of Solitude to terraform the Earth into Krypton.
1 Lex Luthor
If anyone has managed to best Superman, enter his Fortress, and nearly defeat him dozens of times over various media, it's Lex Luthor. His arch enemy and greatest human foil, Lex started out as a mad scientist with red hair before turning into the more familiar bald criminal mastermind he's portrayed as today. As CEO of his own company, Lex has dabbled in unethical experiments and schemes, some of which are done exclusively to oppose his enemies. Fueled by his immense hatred of Superman, he's committed numerous heinous and selfish acts over the years, many of which result in the death of others, and his wealth and influence allow him to appear as a respectable citizen in the city of Metropolis.
Being the popular man that he is, Lex has been portrayed in film and TV by such actors as Gene Hackman (the original Superman films), Kevin Spacey (Superman Returns), Clancy Brown (Superman: The Animated Series), Michael Rosenbaum (Smallville), and Jesse Eisenberg (Batman v Superman: Dawn of Justice). Nearly all versions of the character have broken into the Fortress at some point, save for Eisenberg's, who actually broke into a Kryptonian ship in BvS. Though, since the DCEU Supes doesn't actually have an established Fortress of Solitude just yet, it's close enough for us.
What other big bad bads have broken into Superman's home away from home over the years? Let us know in the comments.