Since season five, James Lucas Scott, known as Jamie, is Nathan and Haley's nine-year old son. He gets his middle name from his uncle and godfather, Lucas Scott. Brooke Davis is Jamie's godmother and they spend much of their time together, and Brooke always gives Jamie a check with "a lot of zeroes" each year on his birthday (it's Jamie's favorite present). Jamie is often a shoulder to lean on for many of the characters and is shown to be very intelligent and cute. He forms a close bond with his grandfather, Dan Scott, as he feels everyone deserves a friend. After Dan reveals to him he was the person who killed Keith, Jamie feels lost. Lucas takes him to the auto shop where he grew up to tell him about Keith. Jamie later forgives Dan.

Jamie is shown to be a good basketball player and has a strong friendship with Skills and Mouth. Jamie is very fond of both Brooke and Julian, serving as best man at their wedding. He has had a very big interest in playing baseball, which grew after Julian gave Jamie a glove once worn by Roberto Clemente and he met ace pitching prospect Ian Kellerman. He misses his uncle Lucas greatly and mentions this to his father often. In season eight, he gets braces for his teeth and has a growing attraction for female classmate Madison, allowing her to win the school spelling bee. He also helps his father study for his college course. In season eight he becomes a big brother to Lydia Bob Scott. He is seen to love his baby sister. In season nine, after Nathan goes missing, Jamie fears that he'll never see him again and repeatedly watches the last video Nathan had sent to him before disappearing.

When Lucas returns to Tree Hill, Jamie and Lydia leave with their uncle allowing Haley to relieve some stress as she awaits word on Nathan. In the series finale time jump, Jamie is now a teenager and the new All-Time Leading Scorer, having broken Nathan's record and wears the number #12 because it is his favorite number.