Jacob Tremblay (born October 5, 2006) is a Canadian actor. He became known for his role as a child born in captivity in Room (2015), for which he won the Critics' Choice Movie Award for Best Young Performer and became the youngest nominee for the Screen Actors Guild Award for Outstanding Performance by a Male Actor in a Supporting Role.

Tremblay subsequently starred as a child with Treacher Collins syndrome in the drama Wonder (2017) and a naive sixth grader in the comedy Good Boys (2019). He has since taken on voice roles as Damian Wayne / Robin in Harley Quinn (2019), the title character in Luca (2021), and Flounder in the The Little Mermaid (2023). He expands into more mature roles in 2026, portraying a young Ted Kaczynski in the upcoming Netflix biographical crime drama Unabomber for Netflix and voicing Curtis Mehlberg in the stop-motion fantasy epic Wildwood from Laika.