Deanna Dunagan (born May 25, 1940) is an American actress. While principally active as a stage actress, she has also worked in television and film. She is best known for her Tony Award-winning portrayal of Violet Weston in Tracy Letts' August: Osage County and for her portrayal of Nana in M. Night Shyamalan's 2015 film The Visit. She has also appeared in the recurring roles of Mother Bernadette on the Fox television series The Exorcist and Mrs. Charles on Chicago Med. She portrayed Dr. Willa Sipe in the 2018 film An Acceptable Loss by writer Joe Chappelle; and starred as Sharon in the 2021 film Stillwater alongside Matt Damon and Abigail Breslin.