After making her name on the New York stage, McDonnell began booking TV and film roles in the early 1980s. Able to exude intelligence and compassion, the actress was well used in a series of roles, notably as a white woman raised by American Indians in 1990's Dances With Wolves and as a paraplegic soap star in 1992's Passion Fish, earning Oscar nods for both performances. In her forties, she looked to the small screen for more fruitful parts, and turned in a slew of solid performances in myriad TV movies. A recurring role on ER as a do-gooder in denial (an Emmy-nominated role) sparked her interest in series television, and in 2003 she landed the plum part of a reluctant president on the lauded revamp of Battlestar Galactica. In 2009, she began appearing on The Closer as a headstrong police captain who goes toe-to-toe with Kyra Sedgwick's character. Off camera, McDonnell is married to fellow actor Randle Mell, and the pair have two children.
- Made her stage debut in 1978, appearing in Sam Shepard's Pulitzer Prize-winning play Buried Child.
- Was in the Portland Stage Company with Sarah Jessica Parker, and lived in the same apartment house.
- Taught drama at Vassar College summer theater in the mid-1980s, and later at the New York Stage and Film Company.
- Husband Randle Mell played a homeless man opposite her in the 1991 movie Grand Canyon.
- Has worked twice with director John Sayles, on 1987's Matewan, her first major film role, and 1992's Passion Fish, for which she garnered an Oscar nomination.
- Like George Clooney, she appeared on the short-lived CBS sitcom titled E/R before landing a role on the famous drama ER (as Noah Wyle's mother).
- Has played both a First Lady (in Independence Day) and a President (in Battlestar Galactica).
- 1991, Golden Globe — Best Performance by an Actress in a Supporting Role in a Motion Picture: Nominee
- 1992, Oscar — Best Performance by an Actress in a Leading Role: Nominee
- 1990, Oscar — Best Performance by an Actress in a Supporting Role: Nominee
- 2011, Emmy — Outstanding Guest Actress in a Drama Series: Nominee
- 2012, Independent Spirit Awards — Robert Altman Award: Winner
- 1993, Golden Globe — Best Performance by an Actress in a Motion Picture - Drama: Nominee
- 2002, Emmy — Outstanding Guest Actress in a Drama Series: Nominee
- Olivia Mell — Daughter
- Michael Mell — Son
- Randle Mell — Husband
- Attended State University of New York, Fredonia, New York, United States