Mary McCormack
A veteran of smart American television, Mary McCormack broke through as attorney Justine Appleton in 'Murder One' (1995-1997), then joined 'The West Wing' (2004-2006) as national security adviser Kate Harper and led the witness-protection drama 'In Plain Sight' (2008-2012) as marshal Mary Shannon. Born in Plainfield, New Jersey, in 1969, she has punctuated her TV career with films such as 'Deep Impact' (1998), 'True Crime' (1999), 'K-PAX' (2001) and the horror hit '1408' (2007), and more recently appeared in 'The Pitt' (2025). Dry wit and unforced authority define her screen presence.
Mary McCormack
33 Movies
22 Series
A veteran of smart American television, Mary McCormack broke through as attorney Justine Appleton in 'Murder One' (1995-1997), then joined 'The West Wing' (2004-2006) as national security adviser Kate Harper and led the witness-protection drama 'In Plain Sight' (2008-2012) as marshal Mary Shannon. Born in Plainfield, New Jersey, in 1969, she has punctuated her TV career with films such as 'Deep Impact' (1998), 'True Crime' (1999), 'K-PAX' (2001) and the horror hit '1408' (2007), and more recently appeared in 'The Pitt' (2025). Dry wit and unforced authority define her screen presence.
Movies
Plays Andrea Baker
Deep Impact
1998
Plays Lilly Enslin
1408
2007
Plays Michelle Ziegler
True Crime
1999
Plays Rachel Powell
K-PAX
2001
Plays Myrna Foy
Miracle on 34th Street
1994
Plays Mother
Vicious
2025
Plays Linda
Full Frontal
2002
Plays Gloria Nesstra
Gun Shy
2000
Plays Alison Stern
Private Parts
1997
Plays Donna Biebe
Mystery, Alaska
1999
Plays Ellen
Drone
2017
Plays Grace Finney
Dickie Roberts: Former Child Star
2003
Plays Lexi
Right at Your Door
2006
Plays Debra Clarke
Unpregnant
2020
Plays Pilgrim Woman
For Your Consideration
2006
Plays Anne
The Broken Hearts Club: A Romantic Comedy
2000
Plays Sarah Schwab
The Crash
2017
Plays Sarah
Backfire!
1995
Plays Frances
High Heels and Low Lifes
2001
Plays Monique
The Big Tease
1999
Plays Agent Becka Anslinger
Harvest
1999
Plays Sally
The Alarmist
1998
Plays Rebecca
Alien Code
2017
Plays Bonnie McCormick
Madison
2005
Plays Phoebe
BigLove
2001
Plays Ellen
Should've Been Romeo
2012
Plays Margaret
World Traveler
2002
Plays Anna
Other Voices
2000
Plays Amanda
A Country Called Home
2016
Plays Moira
Colin Fitz
1997
Plays Leila Lee
Getting to Know You
1999
TV Shows
Plays Mary Shannon
In Plain Sight
2008
Plays Kate Harper
The West Wing
1999
Plays Justine Appleton
Murder One
1995
Plays Peggy Cleary
The Kids Are Alright
2018
Plays Willie Day
Heels
2021
Plays Maggie Morris
K Street
2003
Plays Caroline Yoder
Welcome to the Family
2013
Plays Casey
Loaded
2017
Plays Denna Altshuler
House of Lies
2012
Plays Beth Eckhart
The Wright Verdicts
1995
Plays Debbie
ER
1994
Plays Carole McKay
Traffic
2004
Plays Abigail Liukin
Angie Tribeca
2016
Plays Janet
Will & Grace
2017
Plays Molly Levy
The Newsroom
2012
Plays Dr. Linda Conley
The Pitt
2025
Plays Kathy DeSantis
Divorce
2016
Plays Rickie the Bartender
Law & Order
1990
Plays Lisa Elliot
Scandal
2012
Plays Chloe Daniels
For the People
2018
Plays Anne Finley
The L Word: Generation Q
2019
Plays Mary Shannon
Law & Order: Criminal Intent
2001
Latest Trailers
Watch Trailer
Vicious
Full Filmography
The Pitt
Dr. Linda Conley · 2 episodes
2026
TV
Vicious
Mother
2025
Film
The L Word: Generation Q
Anne Finley · 1 episode
2022–2023
TV
Heels
Willie Day · 16 episodes
2021–
TV
Unpregnant
Debra Clarke
2020
Film
Will & Grace
Janet · 2 episodes
2017–2019
TV
For the People
Chloe Daniels · 1 episode
2018
TV
The Kids Are Alright
Peggy Cleary · 23 episodes
2018–
TV
Loaded
Casey · 8 episodes
2017
TV
Photos
Frequently Asked Questions
How old is Mary McCormack and where are they from?
Mary McCormack is 57 years old, born on February 8, 1969 in Plainfield, New Jersey, USA.
What are the most famous roles of Mary McCormack?
Mary McCormack is best known for roles in 1408, Deep Impact, K-PAX.
How many movies has Mary McCormack been in?
Over a 32-year career (since 1994), Mary McCormack has appeared in 33 movies and 22 TV shows.
What was Mary McCormack's first movie?
The career of Mary McCormack began with Miracle on 34th Street (1994).
What is Mary McCormack's most recent movie or series?
Mary McCormack's most recent release is Vicious, which premiered on August 6, 2025.
What TV shows has Mary McCormack appeared in?
On television, Mary McCormack has appeared in ER, The Pitt, The Newsroom, Law & Order.
Mary McCormack
1969-02-08 · Plainfield, New Jersey, USA
Mary Catherine McCormack is an American actress. She has had leading roles as Justine Appleton on the series Murder One (1995–1997), as Deputy National Security Adviser Kate Harper on The West Wing (2004–2006), as Deputy U.S. Marshal Mary Shannon on In Plain Sight (2008–2012), and as Peggy on the comedy series The Kids Are Alright (2018–2019).