Mary McCormack
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).
Known For
Not in library
1408
2007
Not in library
Deep Impact
1998
Not in library
K-PAX
2001
Not in library
Miracle on 34th Street
1994
Not in library
ER
1994
Not in library
True Crime
1999
Not in library
The Newsroom
2012
Not in library
Law & Order
1990
Not in library
The Pitt
2025
Not in library
Scandal
2012
Acting
2025
Vicious
as Mother
2025
The Pitt
as Dr. Linda Conley
(2 episodes)
2023
National Memorial Day Concert
as Self
2021
Heels
as Willie Day
(16 episodes)
2020
Unpregnant
as Debra Clarke
2019
Treehouse
as Lilith
2019
Still Laugh-In: The Stars Celebrate
as Self
2019
The L Word: Generation Q
as Anne Finley
(1 episode)
2018
The Kids Are Alright
as Peggy Cleary
(23 episodes)
2018
For the People
as Chloe Daniels
(1 episode)
2018
25 Words or Less
as Self
(26 episodes)
2018
25 Words or Less
2018
25 Words or Less
as Mary McCormack
(1 episode)
2017
The Crash
as Sarah Schwab
2017
Drone
as Ellen
2017
Alien Code
as Rebecca
2017
Loaded
as Casey
(8 episodes)
2017
Will & Grace
as Janet
(2 episodes)
2016
A Country Called Home
as Amanda
2016
An American Girl Story: Maryellen 1955 - Extraordinary Christmas
as Kay Larkin
2016
Chelsea Does
as Herself
(1 episode)
2016
Chelsea
as Self
(2 episodes)
2016
Divorce
as Kathy DeSantis
(1 episode)
2016
Angie Tribeca
as Abigail Liukin
(3 episodes)
2016
Match Game
as Self - Panelist
(1 episode)
2016
To Tell the Truth
as Self - Panelist
(1 episode)
2014
Scooby-Doo! WrestleMania Mystery
as Ms. Richards (voice)
2013
Escape from Polygamy
as Leann
2013
Welcome to the Family
as Caroline Yoder
(9 episodes)
2012
Should've Been Romeo
as Ellen
2012
The Unprofessional
as Hilary Pfeiffer-Dunne
2012
House of Lies
as Denna Altshuler
(7 episodes)
2012
Scandal
as Lisa Elliot
(1 episode)
2012
The Newsroom
as Molly Levy
(2 episodes)
2009
Watch What Happens Live with Andy Cohen
as Self - Guest
(1 episode)
2009
Late Night with Jimmy Fallon
as Self
(1 episode)
2008
In Plain Sight
as Mary Shannon
(61 episodes)
2007
1408
as Lilly Enslin
2006
Right at Your Door
as Lexi
2006
For Your Consideration
as Pilgrim Woman
2005
Madison
as Bonnie McCormick
2005
The Late Late Show with Craig Ferguson
as Self
(2 episodes)
2004
Traffic
as Carole McKay
(3 episodes)
2003
Dickie Roberts: Former Child Star
as Grace Finney
2003
The Ellen DeGeneres Show
as Self
(1 episode)
2003
K Street
as Maggie Morris
(10 episodes)
2002
Full Frontal
as Linda
2002
World Traveler
as Margaret
2001
K-PAX
as Rachel Powell
2001
High Heels and Low Lifes
as Frances
2001
BigLove
as Phoebe
2001
Law & Order: Criminal Intent
as Mary Shannon
(1 episode)
2000
The Broken Hearts Club: A Romantic Comedy
as Anne
2000
Gun Shy
as Gloria Nesstra
2000
East of A
as Daphne
1999
The Big Tease
as Monique
1999
Mystery, Alaska
as Donna Biebe
1999
Harvest
as Agent Becka Anslinger
1999
True Crime
as Michelle Ziegler
1999
Getting to Know You
as Leila Lee
1999
The Late Late Show with Craig Kilborn
as Self - Guest
(2 episodes)
1999
The West Wing
as Kate Harper
(48 episodes)
1998
Deep Impact
as Andrea Baker
1998
54
as New Year's Eve Wife (uncredited)
1998
The Alarmist
as Sally
1997
Private Parts
as Alison Stern
1997
Colin Fitz
as Moira
1997
Fathers' Day
as Virginia Farrell (uncredited)
1997
Murder One: Diary of a Serial Killer
as Justine Appleton
1995
Backfire!
as Sarah
1995
Murder One
as Justine Appleton
(41 episodes)
1995
The Wright Verdicts
as Beth Eckhart
(7 episodes)
1994
Miracle on 34th Street
as Myrna Foy
1994
ER
as Debbie
(6 episodes)
1992
The Tonight Show with Jay Leno
1990
Law & Order
as Rickie the Bartender
(1 episode)
1956
Tony Awards
as Self - Nominee
(1 episode)