Jaeden Martell, born Jaeden Lieberher on January 4, 2003, is an American actor who rose from a celebrated child star to a leading man in major Hollywood productions, most notably for his defining role in the blockbuster horror adaptation of Stephen King's novel. His career began with a standout performance in the comedy-drama St. Vincent (2014), where he starred alongside Bill Murray and Melissa McCarthy. Playing the young boy Oliver who befriends the curmudgeonly title character, Martell earned widespread acclaim for his naturalistic and heartfelt performance, receiving a nomination for the Critics' Choice Movie Award for Best Young Performer. This early success quickly led to a role in director Jeff Nichols' science fiction film Midnight Special (2016), where he portrayed the central child with mysterious powers, further solidifying his reputation as a talented young actor capable of carrying complex narratives.

Martell's breakthrough came in 2017 when he was cast as Bill Denbrough, the leader of the Losers' Club, in Andy Muschietti's supernatural horror film It. The film became a massive cultural and commercial phenomenon, with Martell’s portrayal of the stuttering, determined boy at the heart of the story earning him widespread recognition. He reprised the role in the sequel It Chapter Two (2019), which continued the story of the characters as adults. In between these two blockbusters, he took on the title role in the drama The Book of Henry (2017) and starred in the psychological horror film The Lodge (2019), showcasing his versatility in both emotional and chilling genres. He also joined an ensemble cast in Rian Johnson's acclaimed mystery comedy Knives Out (2019), playing the grandson of the wealthy family at the center of the murder investigation.

Seeking more mature and challenging material, Martell starred in the Apple TV+ miniseries Defending Jacob (2020), a legal drama in which he played Jacob Barber, a reserved teenager accused of murdering a classmate. The role allowed him to explore darker, more ambiguous territory alongside Chris Evans and Michelle Dockery. He continued this trend with the heavy metal comedy Metal Lords (2022), where he played a teenage drummer forming a band, and the Stephen King adaptation Mr. Harrigan's Phone (2022), a horror-drama about a young boy who communicates with his deceased mentor through a smartphone. In 2024, Martell starred in the apocalyptic comedy Y2K, directed by Kyle Mooney, a film that satirizes the turn-of-the-millennium panic. With a career that has seamlessly transitioned from acclaimed child actor to a respected young adult performer, Jaeden Martell continues to be a sought-after talent in both mainstream and independent film.