The show began with nine main characters in its first season. After that, characters from that first season left the show, with new main characters having been both written in and out of the series. Originally, it followed two half-brothers Lucas and Nathan Scott who started out as enemies but later formed a close bond as brothers. It also followed the brothers' various relationships with other female leads during their high-school years and in their early twenties. The series ultimately spanned nearly fifteen years across nine seasons, with various time jumps taken into account.
Chad Michael Murray was the first person to be cast for One Tree Hill. The producers were originally unsure as to who Murray would play. Series creator Mark Schwahn wanted him to play the character of Nathan Scott since Murray had played a bad guy several times before, he felt it was only natural to give him this role. Murray, however, wanted to portray Lucas due to a connection he felt with the character. He felt that he could inhabit the character as the two share several similarities. Murray's mother left him when he was young, and Lucas was abandoned by his father . Murray's passion for the role led the producers to cast him as Lucas. Murray had turned down the lead role of Ryan Atwood in The O.C. to accept the role of Lucas Scott. James Lafferty was later cast in the role of Nathan as he was a great basketball player.
Hilarie Burton, auditioned for the part of Ed Harris's daughter in the film Radio. She was encouraged by subsequent callbacks, but did not land the role. However, the casting department remembered her and asked her to send an audition tape for One Tree Hill, and producers promised her a character that she could sink her teeth into – Peyton. " is an old soul," said Mark Schwahn, the series' creator. "She's great. She's always just thrilled to do the job, even though she's kind of new to acting. She's just a joy to be around." Burton said, "I've never studied acting or anything because I've been so lucky with MTV. I'm convinced I got the chance to be on One Tree Hill because I did a guest thing on Dawson's Creek as myself, when the cast appeared at the MTV Beach House." She added, "And my only scene was with Chad Michael Murray (Lucas Scott). So, now The Chad and I are reunited. How bizarre is that?"
The following is a list of series regulars from One Tree Hill.
Portrayed by Chad Michael Murray from season one till six, Lucas Eugene Scott is Haley's best friend and Nathan's half-brother. He and Nathan started on bad terms but later become close brothers. He is a star on the high school basketball team. He had to quit playing the sport after he found out he had a genetic heart problem, inherited from his father - this meant he had more time to focus on writing. He was involved in a complicated love-triangle between Brooke and Peyton, but eventually realized Peyton was the one for him. After Peyton temporarily turned down his proposal because she told him she was not ready, he begins dating his book editor Lindsay and gets engaged. Peyton returns to Tree Hill to get him back and after Lindsay realizes Lucas still loves Peyton she leaves him at the altar. Lucas tells Peyton he hates her and wishes she never came back to Tree Hill because she ruined his life. They later make amends and get married and have a daughter "Sawyer Brooke Scott". Lucas is currently traveling with Peyton, Karen and Andy, while raising Sawyer and writing a new book. Lucas returned in season nine to help Haley deal with Nathan's disappearance by taking the kids with him.
Portrayed by James Lafferty since the pilot, Nathan Royal Scott was a basketball player for the Charlotte Bobcats, husband of Haley James Scott and the father of James Lucas Scott and Lydia Bob Scott. He originally started out as a villain and enemy of his brother, Lucas. After falling for Lucas's best friend, Haley, he becomes a better person and later forms a strong bond with his brother. During the course of his life he has experienced many obstacles including spending time in a wheelchair following an accident after a fight; dealing with an overbearing father; an alcoholic-drug addict mother; allegations he cheated on Haley. Nathan overcomes all of his problems throughout the series and vows to never raise his child the way Dan raised him. Nathan maintains a strong bond with his mother, who was at one point Jamie's nanny. After waiting for Haley to go into labor, Haley gives birth to Lydia Bob Scott. In season nine, he is traveling a lot as an agent but when returning to Haley, Jamie and Lydia he is taken by some people that are getting paid to kill him. After some time Nathan is rescued by Chris Keller, Dan and Julian, but Dan is critically injured after taking a bullet meant for Nathan. At the hospital, Nathan tells Dan that despite everything he ever did, he is still his father and he forgives him, with Dan dying shortly after. In the final episode time jump, Nathan is seen with everyone else at Jamie's basketball game who has since broken Nathan's record for all time scorer.
Portrayed by Hilarie Burton from the pilot until the season six finale, Peyton Elizabeth Sawyer, was introduced in the first season as Nathan Scott's on-and-off girlfriend. She has a huge love for music and for art, and frequently sketches certain events in her life, or feelings she cannot bring herself to tell anybody about. Peyton develops feelings for Lucas Scott in the first season, but frequently tries keeping them to herself since he was consistently off-and-on with Brooke for the first four seasons. Her adoptive mother died in a car accident when she was young, and her adoptive father works out on the sea, which leaves Peyton on her own for most of the first four seasons. She met her birth mother Ellie Harp near the end of the second season, however she also dies from cancer by the middle of the third season. Peyton was consistently surrounded by terrible events: she was shot in the leg during the school shooting in season three and lost a lot of blood, but was rescued by Lucas, and was brutally attacked twice by Ian Banks, who pretended to be her long-lost brother Derek. She was saved the first time by Lucas and her real brother, and the second time by Brooke. Peyton left for Los Angeles to work as an intern at a major record label at the end of season four, but did not enjoy herself or feel she was accomplishing anything, so she returned to Tree Hill in the season five premiere. Peyton eventually married Lucas near the end of season six, and the two had a daughter, Sawyer Brooke Scott. Peyton and Lucas leave Tree Hill to raise Sawyer on the road, alongside Lucas's mother Karen, her daughter Lily, and her boyfriend Andy.