Linda Blair is an American actress best known for her role as the possessed child, Regan, in the horror film The Exorcist. TONY Blair is a British politician who served as Prime Minister of the United Kingdom from 1997 to 2007. Janet Blair was an American actress and singer who appeared in many films and television shows during the 1940s and 1950s. Brit Marling is an American actress, screenwriter, and producer who has starred in several independent films.