Lucas Eugene Scott is a fictional character and the main protagonist from The WB/CW television series One Tree Hill created by Mark Schwahn and portrayed by Chad Michael Murray. Lucas is a talented basketball player and writer and the paternal half-brother of Nathan Scott. The relationship between the two of them is one of the show’s foundations: from being initially estranged and rivals, their dynamic gradually shifts over the course of the series as they set their differences aside and their bond becomes increasingly stronger, turning them into true companions and best friends first and then growing to the point that they eventually begin to truly consider themselves brothers. While striving for his dreams, Lucas also has to deal with his tumultuous relationship with his father, Dan Scott, and is initially the centre of a love triangle designed between him and female leads Peyton Sawyer, whom he’s actually loved since childhood, and Brooke Davis. Ultimately, Peyton turns out to be the one for him, while the relationship between the two of them has become another cornerstone of the show. Haley James, the third female lead and Nathan’s eventual wife, is his best friend since childhood.

The character has been described as popular among teenagers and young adults, not only for his skill at basketball but for his romantic aspirations. Specifically regarding the character's impact on female viewers, Entertainment Weekly stated that his soulful eyes contributed to the show's success.

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, and 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 as Lucas Scott.

Schwahn said that in designing the show, he created Lucas as "this underdog kid from the wrong side of the tracks" who crosses over to the pretty and popular; he wanted to show what the life of such a person would be like in a basketball atmosphere.

For Murray, in addition to their shared abandonment issues, Lucas's love for literature also appealed to him. Murray had become a fan of the medium during high school, and felt it changed his way of seeing things; it made him rethink his own actions. Lucas has been described as "caught between being charming and a nerd, a hermit and confident". Murray said of the character, "He's very introverted." He described Lucas as an observer, someone who likes to watch people and try to figure out who they really are, as opposed to who they think they are, another aspect similar to Murray's own personality.

Murray never played much basketball before the show, and was more into football while in high school. Because of this, a basketball coach was hired for Murray in order to improve his basketball skills. To go along with the character's personality, a "sedate" wardrobe was designed. Schwahn said of Lucas's wardrobe, "...He was a Levi's guy. He was, you know, he wore a lot of, like, plain T-shirts and things because we just wanted him to represent the everyman." Despite having the character start out this way, the series eventually let his wardrobe evolve. Starting from the fourth season on, he was given some "wilder stuff". Schwahn clarified, "You know, he can [now] rock something from Sean John, which normally would have been Nathan's department." He said the style of the characters really does evolve on the show, especially with the four-year timeline jump.

One Tree Hill's costume designer, Carol Cutshall, stated, "Diesel is so wonderful on [Murray]. Diesel jeans. It's an Italian company. A lot of times, Italian designers cut much more slimly...for a really lean physique." For the adult Lucas, she said that "they've had nice long sleeves and nice long shirts and really slim clothing and that looks best on [Murray]. He doesn't need to be swallowed up. He's got his own style as a person. It's not just up to me. I try to bring in what I think is going to fit him best." With the timeline jump, Lucas's main brands became Diesel, Guess menswear, and Juicy Couture.

Regarding the character's romantic life, Schwahn designed a love triangle between Lucas and the two female leads of the show, Peyton Sawyer, who turned out to be the one for him (although he had actually loved her since childhood), and Brooke Davis, creating an intense fan base rivalry. While describing Lucas and Peyton as soulmates and a "meant to be" pairing, he described Brooke and Lucas as "also genuine" and as having a great dynamic. He acknowledged that the fan bases are large and "very passionate" about their pairings. "There is a huge fanbase dedicated to Brooke and Lucas, and sometimes [those people] feel a bit betrayed, just as the fanbase dedicated to Peyton and Lucas felt betrayed [in Season 2, and parts of Season 3]," said Schwahn. "That tells me that we've done things correctly – that's the strength of a love triangle."