Mary Jo Deschanel (née Weir) is an American actress. She appeared in the film The Right Stuff (1983) and the television series Twin Peaks (1990–1991).

Deschanel was born as Mary Josephine Weir.^[1] Her ancestry includes Irish, French, Swiss, Dutch, and English.^[2] After small television appearances, Deschanel's first major film role was portraying Annie Glenn, the wife of the astronaut John Glenn (played by Ed Harris), in the 1983 film The Right Stuff, an adaptation of the 1979 book of the same name by Tom Wolfe.

In 1984, Deschanel played Betty Fernandez, the remarried former wife of astronaut Dave Bowman (Keir Dullea), in the film 2010: The Year We Make Contact. She also played the role of Mrs. Howard in the 2000 film The Patriot (2000).

Deschanel played Eileen Hayward in the TV series Twin Peaks. She has also appeared in the TV series House in the episode "Simple Explanation" as Julia Kutner, the adoptive mother of recently deceased Dr. Lawrence Kutner.

Deschanel was featured a second time as the wife of a character played by Ed Harris, in the movie Winter Passing (2005), although she was only seen in a photograph on the wall. Despite never physically appearing in this movie, she did receive full billing in the credits as the character "Mary".

She has been married to cinematographer Caleb Deschanel since 1972.^[3] Her daughters, Emily and Zooey, are also actresses.^[4]