Unlike Spider-Man, Superman has rarely had to worry about people knowing who he really was in any of the live-action projects. From Superman & Lois, all the way to the Christopher Reeves movies, the Man of Steel's civilian identity has mostly remained classified information. Batman, his Justice League counterpart, has enjoyed the same level of secrecy too.
However, there have been a couple of times on the DC pages where people got to learn that Superman was Clark Kent. Some of the reveals were followed by serious consequences that affected those around the Metropolis-based hero, whereas the Kryptonian hero managed to handle the mess quite quickly on other occasions.
The Flame Dragon Destroys Clark's Office Attire
In Superman #142, a flame dragon from Krypton shows up in Metropolis and starts burning everything down. When it directs fire at Clark Kent, his suit gets burned up, leaving his Superman costume intact. Lois and the rest of his colleagues thus learn that Clark is Superman.
Ordinarily, Lois tends to know that Clark Kent is Superman but in this continuity, there is an obvious lack of trust because Clark has never bothered to tell her. Though Clark could easily come up with an excuse to explain why he is wearing a Superman costume inside, he doesn't do so because he is forced to step up and use his powers right at that moment, further confirming that he is the popular hero.
Superman Gets Exposed On A Reality TV Show
Seeking a secluded place to change, Clark decides to do so inside a phone booth in Action Comics #345. It turns out there is a hidden camera in the booth that's part of a live reality prank show.
Accidental reveals are always fascinating. Even more interesting is that the show that reveals Superman's identity is Candid Camera, an actual reality show that aired in the '40s. By incorporating a real-life show into the comics, everything feels a bit more realistic, especially in an age where people were still trying to understand the whole Superhero concept.
Superman Confesses To A Terminally Ill Boy
In Action Comics #457, Clark Kent's friend, Pete, informs him about his terminally ill son, Jonathan. whose last wish is to know the identity of Superman. A sympathetic Clark then visits Jonathan and confesses to him before flying him on various missions.
Clark has always had a soft spot for children but doing something special for a terminally-ill child paints him as even more good-hearted. Thanks to the revelation, the child is able to miraculously recover from his illness. That Superman flies Jonathan around on his adventures is a bit unrealistic but the Man of Steel comes off as someone capable of entertaining others too.
Lois Lets The World Know
While going through the dark web, the villain HORDR acquires photos of Superman changing back to Clark Kent in Superman #43. He then uses the information to blackmail him, forcing him to use his lasers to power up his robots. To put an end to the blackmail, Lois decides to tell the whole world the truth.
Lois and Clark make one of the best superhero couples because they always look out for each other. Though Superman would rather commit bad deeds than let everyone know he is Clark Kent, Lois can't sit around and watch him turn evil. By revealing Superman's actual identity, she leaves HIORDR with nothing with which to blackmail the Kryptonian.
Superman Holds A Press Conference
Tired of keeping his secret for so long, the Man of Steel finally decides to hold a press conference in Superman #18. He gathers journalists, as well as a few members of the public before telling them everything.
Superman somehow borrows a leaf from Spider-Man here. In one of the best times that Spider-Man's identity gets exposed in the comics, the web-slinger also holds a press conference as part of the Superhero Registration Act. But while Spider-Man's is in line with the Civil War, Superman only does it out of boredom.
The Mod Mob Finds Out After Attacking The Daily Planet
In Superman's Pal, Jimmy Olsen #132 the Mod Mob captures Jimmy and tortures him into helping them raid the Daily Planet. There, they stage an attack and while Clark is lying on the ground, members of the mob open his shirt to discover that he's Superman.
Since the attack takes place inside the offices, Clark is forced to restrain himself rather than change to Superman quickly. He does this out of fear that his colleagues will find out who he is. Sadly, the hesitation comes at a great cost as Clark now has to deal with being mobbed by civilians every time he steps out.
Mala's Disguise
A Kryptonian outlaw named Mala shows up on Earth in Action Comics #194. She disguises himself as Clark Kent, not knowing that Clark Kent is Superman. When ordinary citizens see 'Clark' do unusual things like bending vehicles, the real Clark is forced to come clean.
Interestingly, despite being arguably one of the most powerful Superman villains, Mala gets shelved after the Golden Age of Comics. She never appears again in the comics after 1954. The only other time she makes an appearance is in Superman: The Animated Series, Since she has the same powers as Clark, keeping her around would have made for some fascinating duels.
Clark Confesses To Lois
After fighting one of the best female DC villains, Silver Banshee, in Action Comics #662, Clark decides to finally confess to Lois that he is Superman. This causes some problems in their relationship but she eventually understands and the two get married.
In all forms of DC media, it takes a while for Clark to tell Lois that he has special abilities. In some stories, he does so when they are teenagers while in others, he does so in adulthood. Here, Lois is stunned by the news because she had been photographing Superman for a long time. And since she hates chaos, she can't imagine continuing to date someone that attracts anarchy wherever he goes. Luckily, they work things out.
Lois Tries To Cut Clark's Hair
In Action Comics #484, Lois tries to cut Clark Kent's hair while he's asleep. Nothing happens and this confirms the suspicion she has had all along.
Secrets always lead to suspicion and that's what happens between Clark and Lois in the Golden Age issue. having suspected for so long, Lois is left with no choice but to try and prove it herself. In the Delilah-like moment, she indeed realizes that his hair is like steel. The revelation disappoints her but she understands.
Clark Tells His Classmates
Tired of Superman getting all the credit. Clark decides to tell his schoolmates that he is the Man of Steel in Adventure Comics #235. Luckily, an amnesia gas is soon released in Smallville, making everyone forget what happened.
The move goes against Clark's personality since he has never been known as a showoff. But he can be excused for it, by factoring in his status as a teenager. A common trope in both DC and Marvel media involves ordinary people being made to forget the revelation and that's what happens again here.