Kathleen Denise Quinlan Abbott (born November 19, 1954) is an American film and television actress. She is best known for her Golden Globe-nominated performance in the 1977 film of the novel I Never Promised You a Rose Garden, and her Golden Globe and Academy Award-nominated role in the 1995 film Apollo 13, along with many roles in other feature films, television movies and series, in a career spanning almost five decades.

She made her feature film debut in Mel Stuart's One Is a Lonely Number (1972) follwed by George Lucas' American Graffiti (1973) and made her definite breakthrough in I Never Promised You a Rose Garden (1977) as Deborah Blake.