Linda Denise Blair is an American actress and activist. Known for her work in the horror genre, she first came to prominence with her portrayal of Regan MacNeil in the film The Exorcist (1973), for which she won a Golden Globe Award and received a nomination for the Academy Award for Best Supporting Actress. The film established her as a scream queen and she reprised her role in two sequels: Exorcist II: The Heretic (1977) and The Exorcist: Believer (2023).

Regan Teresa MacNeil is a fictional character in the 1971 novel The Exorcist and one of the supporting characters in its 1973 film adaptation and the 1977 film Exorcist II: The Heretic, while being one of the main protagonists in the first season of the television series The Exorcist (2016–2017). She was portrayed by Linda Blair in both films and by Geena Davis in the television series. Blair reprised the role in the 2023 film, The Exorcist: Believer.