Pete Ross was a resident of Smallville that figured out that his schoolmate and friend, Clark Kent, was actually Superboy when he saw him changing into Superboy while on a camping trip, but kept this secret to himself. Pete helped Clark's sudden disappearances though he did not tell Clark that he knew his secret. He was also made into an honorary member of the Legion of Super-Heroes. As an adult, Pete finally told Clark that he knew his secret identity when he needed his help to save his son, Jonathan. When Superman refused to help, Pete suffered from a nervous breakdown and was sent to a mental institution, where he resided until his son finally was saved.
After Crisis on Infinite Earths, Pete Ross was not initially aware of his friend Clark's secret identity. It was during his time as Vice-President under Lex Luthor's presidency that Lex Luthor himself actually told Pete the truth. He eventually became President after Lex was sent to jail. He was married to Lana Lang and they had a child together, Clark Peter Ross.
Pete was implicated in being the villain, Ruin, who was really Professor Emil Hamilton. Hamilton had kidnapped Pete, Lana, and their son, but they were all saved by Superman and Peter was later exonerated. Some time after, Lana and Pete divorced and Pete returned to Smallville to raise his son, where he was last seen working in a general store.
The family of Pete felt a strong personal connection to Smallville and its history since had been there since 1870. After the first meteor shower, Jonathan Kent persuaded Pete's family to transfer ownership of the Ross Creamed Corn factory and its surrounding cornfields to LuthorCorp who turned it into a fertilizer plant. Pete and his family felt powerless and betrayed after that.
Pete worked on the Smallville Torch newspaper with Clark Kent and Chloe Sullivan. He and Clark joined the football team together to avoid becoming the scarecrow. Although Clark didn't trust Pete with his secret, he did invite him to help his investigations into the weird and unexplained happenings in Smallville, including investigating their childhood friend Greg Arkin when he became a meteor freak. Pete was popular with girls and went on several dates. When Clark left Lana Lang during their date, Lana let Pete and his date use the limo that Lex Luthor had provided. Pete also started dating Jodi Melville after she lost weight. However, this relationship put him in danger when she almost ate him. Clark saved him just in time. On a field trip to the LuthorCorp plant, Pete along with Chloe was held hostage by Earl Jenkins. Clark saved Pete again, along with Chloe and the rest of the hostages. Clark also saved Pete from the Nicodemus flower. Under the influence of the flower, Pete came close to shooting Lex Luthor after it had lowered his inhibitions. Pete nominated Clark for class president and threw himself into campaigning for Clark. Nevertheless, his efforts failed. After this he got a place of Mayor Siegel's re-election campaign. Pete hid his feelings for Chloe, but was frustrated by Chloe's crush on Clark and Clark's obliviousness to it. Although disappointed that Chloe went to the Spring Formal with Clark, Pete was excited when he arranged for Erica Fox to be his date, as he thought she was the hottest girl in their class.
Pete helped Clark find Jonathan Kent after a tornado hit Smallville. During the search, Chloe confided in Pete about her stalling relationship with Clark. Pete was sympathetic, while hiding his deeper feelings. Pete joined the football team again. When Pete stopped at the scene of an accident, he discovered Clark's spaceship. Against his parents' wishes, Clark felt that he had no choice but to tell Pete the truth about his origins. Pete was furious at Clark for not telling him sooner. He was soon abducted by Dr. Hamilton and tortured, but he proved himself courageous and fiercely loyal by not revealing Clark Kent's secret. This made Pete realize how dangerous the secret was and why Clark kept it from him as long as he could. Pete proved a valuable ally to the Kent Family when Clark was accidentally exposed to Red kryptonite for the first time. No one understood Clark's erratic behavior, but Pete figured out that the red kryptonite ring was to blame. Pete helped Jonathan overpower Clark and destroy the ring, returning Clark to normal. Having learnt about Clark's origins, Pete became more involved with helping Clark defeat criminals and meteor freaks. Pete was injured when Byron Moore attacked him, but Clark ultimately defeated him. Pete also helped Clark defeat Chrissy Parker when she started absorbing people's youth by kissing them. Ryan James, who was telepathic, revealed that Pete was struggling to keep Clark's secret. Nevertheless, Pete helped Clark out of trouble in return for all the times Clark had saved him. He switched Clark's DNA sample with his own to ensure that Clark's Kryptonian origins weren't discovered. He helped Clark move the ship when the feds quarantined the farm and he served as a decoy when Jonathan and Clark recovered the key and transported the ship to the hospital where it restored Martha Kent and Clark's health. Pete also helped Clark bury refined meteor rock. Pete was with Clark when he discovered the Kawatche Caves. Later in the caves, Pete was infected by an alien parasite, which compelled him to do wreckless things, including screaming out in public that Clark was an alien. Fortunately, due to Pete's unusual behavior, nobody believed Pete. When Clark tried to convince Pete to go to the hospital, he used green kryptonite to stop him. He then used red kryptonite to make Clark join in on the fun. Clark eventually saved him, and Pete expressed regret for manipulating Clark the way that he did. Despite his dislike of the Luthors, when Lex introduced Lucas Luthor to him, he invited Lucas to join in his basketball match with Clark. When Clark began to get too competitive, Pete was protective of Clark and reminded him not to use his powers in front of a Luthor. Pete finally angrily confronted Lionel Luthor about taking his family's business to provide a diversion for Clark to super speed into the caves and snatched Lionel's kryptonite key.
Pete was concerned about Clark during his time away from Smallville and showed the Kents a newspaper article about Clark's crimes in Metropolis. Powerless to help Clark, Pete waited patiently for his safe return. Pete helped Clark hide his powers from a journalist when solar flares began to effect his powers. Jonathan acted as a decoy so Pete could take Clark into hiding. However, as they left they received a distressed call from Lana as Perry White was threatening to jump to expose Clark's secret. Clark tried to save him, but now the solar flares had completely depowered him, Clark relied on Pete to save the day, which he managed to do by hoisting them up with the help of his car. Pete finally confessed to Clark that he was struggling to keep Clark's secret when Lex also learned about Clark's powers. Pete tried to convince Clark that Lex could not be trusted with such dangerous information. Pete assisted Clark when he was temporarily blinded. Nathan Dean kidnapped Pete to blackmail Pete's mother, Judge Abigail Ross, while Clark was helpless to intervene. Clark managed to find Pete before Nathan Dean tried to kill him. Clark didn't mind when Pete told everybody his own version of the events, detailing his "heroics." Pete joined the running team and became involved with street racing, giving him the nickname, Pete "The Boss" Ross. However, when his sponsor asked him to purposely blow a street race, and Pete did not comply, the sponsor threatened and blackmailed him for $20,000. Out of fear and desperation, Pete asked Clark to steal money for him. Furious that Pete would put him in that position, Clark had to figure out a way to save Pete, without having to resort to theft. Although Clark managed to save Pete, this deeply effected their friendship. When Chloe was exposed to a kryptonite-based airborne agent, she gained the ability to make anybody tell her the truth, which made Pete blurt out that he'd been in love with her for a long time. Both Chloe and Clark were shocked by this and Pete was extremely embarrassed. When Clark asked why he never told Chloe before, Pete reluctantly admitted that he knew he never had a chance, because he knew Chloe was in love with Clark, and he just couldn't compare. Pete's parents got divorced at the end of his junior year. Rather than deal with the turmoil at home, he began spending the night at the Torch office. Chloe caught him and questioned what he was doing. Pete reacted angrily but eventually confessed what he was dealing with. When Frank Loder began investigating Clark, he targeted Pete, and beat him up. Lex arrived to save him just in time. This made Pete decide to move to Wichita with his mother after the divorce. Although he appreciated Clark's friendship and honesty with him, he confessed that he could no longer stay in Smallville without either being killed or revealing Clark's secret.
Pete returned to Smallville as a roadie with the band OneRepublic. He used kryptonite-laced chewing gum to grant him the ability to stretch and contort his body in bizarre ways. After using this to save Kara Kent from a falling speaker at the OneRepublic concert, he headed to the Kent Farm and reunited with Clark. However, he found it difficult to adjust to the fact that Chloe, Lana, and Lionel were all now keepers of Clark's secret. Seeming almost embittered, Pete expressed his feelings about keeping Clark's secret and what it had cost him. He demonstrated his new power and told Clark that he was going to be a hero now. However, a hesitant Clark tried to convince Pete that using kryptonite was dangerous. In response, Pete angrily declared that if Clark tried to stop him, he would reveal the truth about him and his alien heritage. Pete then went to visit Chloe at the Daily Planet and proudly told her about his powers, having arranged an interview with Jimmy Olsen. His vendetta against Lex was renewed when he learned that Lex was watching Chloe's computer, and he infected that system with a virus. Lex caught him, though, and blackmailed him into stealing Kara's Kryptonian bracelet from Lionel's vault. Clark learned of Pete's intentions and sped to Lionel's office, but Pete stopped him with kryptonite and returned to Smallville with a determination to kill Lex. He ambushed the younger Luthor, but Lex's bodyguard overpowered him and his ability faded as the power of the gum wore off. Pete was tortured as Lex tried to force the location of the bracelet from him, only for Clark to incapacitate both Lex and the guard and rescue Pete.
Pete realized that he was not meant to be superhuman and decided to search for another way to express the hero within him. Wishing Clark and Chloe well, he left Smallville once more.