Teddy Daniels is a fictional character from the psychological thriller film Shutter Island, directed by Martin Scorsese. He is portrayed by actor Leonardo DiCaprio and serves as a U.S. Marshal investigating the disappearance of a patient from a mental institution. As the story unfolds, Teddy grapples with his own traumatic past and the dark secrets of the island. Throughout the film, Teddy's journey is marked by suspense and psychological tension, leading to a shocking twist that challenges the viewer's perception of reality. His character embodies themes of grief, guilt, and the struggle for truth in a world filled with deception.