Initially believed to be an arsonist responsible for a deadly fire, he serves as an enigmatic figure connected to the island's secrets.

A respected psychotherapist and the lead doctor at Ashecliffe Hospital, he plays a crucial role in the unfolding events on Shutter Island.

Introduced as a missing woman accused of murdering her children, her character undergoes multiple transformations throughout the narrative.

Teddy Daniels’ wife, whose death in a fire is central to the emotional and mysterious tensions in the story.

Teddy's partner, a U.S. Marshal whose friendly demeanor and rapport with Teddy add depth to their investigation.

A psychiatrist at Ashecliffe Hospital, he has a personal and professional history with Teddy that influences key events.

A patient at Ashecliffe whose past interactions with Teddy drive the marshal's investigation on the island.

A psychotherapist who works alongside Cawley and presents a contrasting approach to mental health treatment.

An official responsible for security at Ashecliffe Hospital, whose brief appearance introduces deeper philosophical questions about human nature.