Each of the main characters in Smallville discovered the truth about Clark Kent (Tom Welling) being Superman at very different times in the series. Like most superhero stories, one of the most important elements of Smallville was Clark's secret identity. Since the pilot episode, Clark tried to protect the secret of his powers and his Kryptonian heritage from the people around him, but there were times when Clark either failed to hide the truth or was compelled to come clean.

Because of Superman's morality, he'll always be known as the Big Blue Boy Scout, but throughout most of Smallville, Clark Kent found himself in positions where he had to lie and keep secrets from the people closest to him. Despite his best efforts, however, the truth regarding his secret identity was discovered by various main characters. During Smallville's ten-season run, Clark met a number of people he was able to be honest with. With some, Clark came clean willingly, while others had to find out the truth on their own.

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Pete Ross (Season 2, Episode 3)

Sam Jones III as Pete Ross in Smallville

In season 1, the only people Clark could talk to about his powers were his parents, Jonathan (John Schneider) and Martha (Annette O'Toole). It was a great source of angst for him that he couldn't share that part of his life with anyone else. That changed in Smallville season 2 when Clark's best friend, Pete Ross (Sam Jones III), found Clark's spaceship after it got swept up in the tornado from the season 1 finale.

Pete wanted to tell people about the ship, forcing Clark to come up with excuses to stop him. When Clark was blamed for the ship's sudden disappearance, Clark told Pete his secret, knowing that it was the only way to preserve their friendship. Pete learned the truth in season 2, episode 3 "Duplicity." Pete helped Clark keep his secret in seasons 2 and 3, but the burden it presented eventually got the best of him. To escape from it, Pete left the series in the penultimate episode of season 3.

Chloe Sullivan (Season 4, Episode 12 & Season 5, Episode 1)

Chloe at an office smiling in Smallville

In the season 4 episode "Pariah," Clark's girlfriend Alicia (Sarah Carter) became determined to leak his secret to the world, so she tricked Clark into using his powers in front of Chloe Sullivan (Allison Mack). Chloe watched in shock as Clark caught a car with his bare hands.

Hoping he would tell her about his abilities on his own, Chloe said nothing and assumed that Clark was meteor-infected. After unintentionally following Clark to the Fortress of Solitude, Chloe knew that there was more to his secret than she realized. After saving Chloe from freezing to death in the Fortress, Clark finally told Chloe everything in the season 5 premiere "Arrival" — and from then on, Chloe served as Clark's closest ally.

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Lionel Luthor (Season 5, Episode 15)

Lionel Luthor appearing pensive in Smallville

After interacting with one of the Kryptonian Stones of Power, Lionel became a vessel of Jor-El (voiced by Terence Stamp). Through the connection that was established by the Stone, Jor-El was able to take control of Lionel and use him to resurrect Clark when he was killed in Smallville season 5, though Jonathan Kent would die in exchange later in the season.

It was revealed that when Jor-El inhabited Lionel's body, he left behind some of his Kryptonian knowledge (including the truth about Clark's identity) in Lionel's mind. The audience learns for sure that Lionel knows the truth about Clark in the episode "Cyborg." Later, Lionel confessed to Clark that he knew he was Kal-El. Though it took time for Clark and Martha to trust the former villain, he never stopped trying to prove himself to the Kents.

Oliver Queen (Season 6, Episode 4)

Green Arrow taking cover behind a wall in Smallville

Just after his introduction to the series, Oliver Queen (Justin Hartley) was breaking into a museum as the Smallville version of Green Arrow when he was intercepted by Clark, who used his powers to stop him. Oliver, who witnessed Clark's powers firsthand, tried to convince him to use his abilities to benefit the world, rather than just his friends in Smallville. Oliver became the first (and only) major character to figure out Clark's secret within just one episode of meeting him. In fact, both Oliver and Clark learned about one another's secret identities in "Arrow," and keep them secret for one another.

Lana Lang (Season 6, Episode 16)

Tom Welling as Clark Kent and Kristin Kreuk as Lana Lang in Smallville

Clark spent six seasons agonizing over what to do about Lana Lang (Kristin Kreuk) and his secret. Several obstacles prevented him from telling her, ranging from his own fear that she would blame him for the death of her parents (though Lana did find her birth father in Smallville), to his concern that knowing the truth would be too much of a burden for her to bear. In the season 5 episode "Reckoning," Clark finally told her and proposed. Unfortunately, this decision was undone when Clark had to turn back time to stop her from dying. As a result, Clark kept his secret hidden from her for another year.

Related: Why Arrow Recast Oliver Queen (Rather Than Spinoff Smallville)

In season 6, Lana — who knew Clark was hiding something ever since she saw him save her from the tornado — decided that if he wouldn't tell her the truth, she would find it on her own. After setting a trap for Clark on the day of her wedding to Lex (Michael Rosenbaum), she witnessed him using his powers in the episode "Promise." She thought this was the whole story, until Clark told her that he was from another planet in the season 6 finale. Clark admitted to Lana in season 7 that he had no idea why he was ever worried that she wouldn't understand.

Lex Luthor (Season 7, Episode 20)

Michael Rosenbaum as Lex Luthor in Smallville

After becoming a full-fledged villain in season 7, Lex murdered his father and plunged himself deeper into the mystery of the Traveler, the name given to the alien who came to Earth in the meteor shower. After finding the location of the Fortress of Solitude and uncovering a way to gain control over the Traveler, Lex asked Brainiac (in the guise of Laura Vandervoort's Supergirl) who the Traveler was. Brainiac responded, "don't you already know?" implying that Lex had the clues for the Traveler's identity.

Lex apparently put the pieces together, and was not surprised when Clark confronted him in the Fortress for their final battle in the finale, "Arctic." Lex would eventually forget the truth about Clark's identity though when he was infected with a toxin later.

Davis Bloome (Season 8, Episode 18)

Davis Bloome smirking in Smallville

Davis Bloome (Sam Witwer), the human form of Doomsday, suffered from blackouts and was unaware for a long time that he was a Kryptonian monster created to kill Clark. Tess, believing that Clark had to kill Doomsday to become the hero he was fated to be, told Davis about his destiny and his connection to Clark toward the end of season 8. Davis learned the truth about Clark in the episode "Eternal."

Related: Man Of Steel Had An Original Character From Smallville Season 1

Tess Mercer (Season 8, Episode 21)

Tess Mercer looking thoughtful on Smallville

Tess Mercer (Cassidy Freeman) knew there was something up with Clark when she came to Smallville to replace Lex in season 8. Lex's obsession with Clark was enough to give her a few clues. She even orchestrated a plane crash to force Clark into exposing his abilities, but her plan didn't work. Toward the end of season 8 in the episode "Injustice," she uncovered Lionel's journal and found out everything she needed to know about Clark. When she told Clark that she knew the truth, he didn't trust her at first; however, in time, Clark gained enough confidence in Tess to invite her to join Smallville's Justice League.

Jimmy Olsen (Season 8, Episode 22)

Jimmy Olsen taking a picture in Smallville

Jimmy Olsen (Aaron Ashmore) started to suspect that Clark was the Red-Blue Blur (Clark's vigilante identity for season 8), when his research into the hero's rescues pointed him directly at Clark. Clark temporarily alleviated Jimmy's suspicions by arranging for Oliver to pose as the Red-Blue Blur in "Identity," but the truth was exposed once Jimmy saw him heal from a wound in the season 8 finale "Doomsday." Unfortunately, though, Jimmy wasn't in on Clark's secret for long. Jimmy was killed by Davis in the same episode, leading Clark to renounce his humanity.

Lois Lane (Season 9, Episode 21)

Erica Durance as Lois Lane in Smallville

From Smallville seasons 2 to season 6, Clark had to fend off questions from a suspicious Lana, but he didn't have the same problem with Lois Lane (Erica Durance), who remained oblivious to Clark's secret identity for most of the series. While Lois did learn the truth in the season 8 episode "Infamous," time being reversed undid that reveal.

Things took a turn in the Smallville season 9 finale "Salvation," when Clark (as the Blur) saved Lois from Zod (Callum Blue) and kissed her. After he left, Lois was able to tell from the kiss that Clark was the Blur all along. However, she didn't tell Clark about this, and just as Chloe did in season 4, she waited for Clark to tell her himself. In the season 10 episode "Isis," Clark confessed to Lois that he was the Blur, and was surprised to find out that she already knew.

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Why Clark Kent Is A Terrible Disguise For Superman

Clark Kent in glasses and a trench coat in Smallville

Although it's been a crucial component since he first debuted in comic books in 1938, Superman's secret identity as Clark Kent is flimsy at best. Most of the Smallville characters who learn that Clark Kent has powers or is the secret identity of The Blur find out after being told or witnessing him using those powers. In all likelihood, however, people could very easily put two and two together just from basic observation.

Not only does Clark Kent look exactly like the ever-maskless Blur (except for the insignificant addition of glasses), but the journalism cover for why Kent always happens to be nearby when the hero is active would fall apart under anything but the most basic scrutiny – and he works in a building full of investigative journalists who'd spot him a mile away.

At the same time, however, its obviousness is exactly what makes Superman's Clark Kent identity the perfect disguise. The best lies are those that most closely mirror the truth. More importantly, the silliness of The Blur's secret identity helps give Smallville its comic book charm.

Superman Never Appears In Smallville

Clark Kent becomes Superman in Smallville

Smallville, with its focus on Clark Kent as a teenager, always appeared to be a Superman origin story. While that is true to an extent, the Superman persona of Clark Kent never appears in the show. In fact, Clark never wears a cape or tights at all, not even when he’s nicknamed The Blur by Lois Lane in an article. Fans might have expected Clark to end his time in the show having evolved into Superman, but there’s a reason he didn’t.

Related: Clark's Crisis Ending In Smallville Wouldn't Have Worked With Lana

Before the show even began filming the pilot episode, there was a strict, “no tights, no flight” rule for Smallville. Clark eventually learned to control his powers of flight in the show, but he still didn’t get a superhero suit. Tom Welling has spoken extensively in interviews in the past about playing Clark, not Superman, for the show. In his mind, once Clark Kent became Superman, he was no longer a struggling young man figuring out how to be the good guy, but a fully-fledged hero. Even when Smallville came to an end, Welling believed Clark still had more learning to do before he fully became Superman.

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