She is best known for her role in the movie The Exorcist ( 1973 ) . Blair is best known for her role as the possessed child , Regan , in the 1973 acclaimed blockbuster The Exorcist , for which she was nominated for an Academy Award and two Golden Globes , winning one . She reprised her role in 1977 's Exorcist II : The Heretic , a controversial sequel which had a poor response with both audiences and critics .