Mary McCormack is an American actress best known for her television roles as Justine Appleton on Murder One (1995-1997), as Kate Harper on The West Wing (2004-2006) and as Mary Shannon on In Plain Sight, from 2008-2012.
She also had a recurring character on ER and starred in Right At Your Door, which premiered at the 2006 Sundance Film Festival. She was also seen opposite John Cusack and Samuel L. Jackson in Stephen King's thriller, 1408.
McCormack's breakout performance opposite Howard Stern in Private Parts won her universal critical acclaim. She followed that film with a highly successful run opposite Alan Cumming as Sally Bowles in the Sam Mendes and Rob Marshall-directed Broadway production of Cabaret for the Roundabout Theatre Company.
Some of McCormack's additional television and feature credits include the following: the Steven Soderbergh and George Clooney political series for HBO, K-Street; the miniseries Traffic, Dickie Roberts: Former Child Star opposite David Spade; K-Pax opposite Jeff Bridges and Kevin Spacey; High Heels & Low Lifes with Minnie Driver; Mystery, Alaska written by David E. Kelley and starring Russell Crowe; Other Voices with Stockard Channing and Campbell Scott; The Broken Hearts Club opposite John Mahoney and Timothy Olyphant; The Big Tease opposite Craig Ferguson; Gun Shy with Sandra Bullock and Liam Neeson; the Clint Eastwood film True Crime; Mimi Leder's Deep Impact; The Alarmist opposite Stanley Tucci; and Miracle on 34th Street.
Additional stage credits include the acclaimed London stage production of Neil LaBute's play Bash and the David Warren-directed productions of My Marriage to Ernest Borgnine and A Fair Country.
Born in Plainfield, New Jersey, McCormack is a graduate of Trinity College and resides with her family in Los Angeles.