Lucas Eugene Scott is the illegitimate son of Dan Scott and Karen Roe, who were high school sweethearts. When Lucas was a child, his father never publicly claimed him as his own. Instead, he found a father figure in Dan's brother Keith. As a young teen, Lucas enjoys literature, working at his uncle's car repair shop, hanging out with his best friend Haley James, and playing basketball at the river court. It is the latter hobby that gets Lucas noticed by the high school basketball coach who encourages Lucas to join the team that his half-brother and nemesis is a member of. Lucas hesitates but eventually decides not to let his family get in the way of his goals. After many trials, he and Nathan eventually form a friendship and a brotherly bond.
Lucas has a serious heart condition, hypertrophic cardiomyopathy (HCM) which he discovered after his father had a heart attack. Lucas' relationship with Dan was always very complicated and became even more so when Lucas discovered that Dan both wanted Karen to get an abortion and desired joint custody when Lucas was young. The first time Dan owns up to being Lucas' father is after a serious car accident when the only way the boy could get immediate treatment was from parental permission thereby, he saved Lucas' life. Lucas returned the favor some time later when he saved Dan from a fire in the dealership. Of course, Lucas later came to regret this action when he realized that Dan was the man that took Keith's life in cold blood.
A romantic at heart, Lucas has had several loves, most notably, however, were his relationships with Peyton Sawyer and Brooke Davis. He and Brooke first got together casually but, after breakups and indiscretions, Lucas decided to make things more serious with her. The relationship with Brooke was never short on drama as there was a pregnancy scare and repeated cheating on Lucas' part with his girlfriend's best friend. At the end of his senior year, Lucas - with the blessings from his former flame - realizes his love for Peyton (although this preference was really discussed among fans of the show). When they are 19, Lucas proposes to Peyton with the ring his now-dead uncle was going to give Karen. She asks him to wait until they are more settled, which Lucas translates as a termination of the relationship. He falls for his book editor, Lindsay, but she leaves him at the alter when she realizes that the second book he has been writing is about Peyton.
After alot of back and fourth, Lucas finally realizes that Peyton is the girl he really loves, and he proposes to her. They are now engaged to be married.
After their wedding Peyton is carried to the hospital by Lucas where she has their baby Sawyer Brooke Scott. Peyton and Lucas leave the show at the end of season 6 - it is not seen in the show or never understandable where are they living. (Lucas returns only for a small role in season 9)