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.