Mary McCormack
Acting
Biography
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).
As actor 77
Watch What Happens Live with Andy Cohen
2009
Law & Order
1990
Law & Order: Criminal Intent
2001
The Pitt
2025
The Late Late Show with Craig Ferguson
2005
Jimmy Kimmel Live!
2003
The West Wing
1999
Tony Awards
1956
The Tonight Show with Jay Leno
1992
ER
1994
Scandal
2012
25 Words or Less
2018
The Ellen DeGeneres Show
2003
Late Night with Jimmy Fallon
2009
The Newsroom
2012
Chelsea
2016
Will & Grace
2017
In Plain Sight
2008
House of Lies
2012
Angie Tribeca
2016
To Tell the Truth
2016
Match Game
2016
Deep Impact
1998
Murder One
1995
The L Word: Generation Q
2019
1408
2007
The Late Late Show with Craig Kilborn
1999
Divorce
2016
For the People
2018
Heels
2021
K-PAX
2001
True Crime
1999
Vicious
2025
Miracle on 34th Street
1994
Gun Shy
2000
54
1998
The Kids Are Alright
2018
Traffic
2004
Private Parts
1997
Drone
2017
Full Frontal
2002
Fathers' Day
1997
Alien Code
2017
Mystery, Alaska
1999
Welcome to the Family
2013
K Street
2003
Treehouse
2019
Dickie Roberts: Former Child Star
2003
The Broken Hearts Club: A Romantic Comedy
2000
Scooby-Doo! WrestleMania Mystery
2014
For Your Consideration
2006
Loaded
2017
Backfire!
1995
High Heels and Low Lifes
2001
Unpregnant
2020
The Wright Verdicts
1995
The Alarmist
1998
The Big Tease
1999
Escape from Polygamy
2013
The Crash
2017
Chelsea Does
2016
Right at Your Door
2006
The Unprofessional
2012
Murder One: Diary of a Serial Killer
1997
BigLove
2001
World Traveler
2002
Still Laugh-In: The Stars Celebrate
2019
Harvest
1999
Madison
2005
A Country Called Home
2016
An American Girl Story: Maryellen 1955 - Extraordinary Christmas
2016
Should've Been Romeo
2012
National Memorial Day Concert
2023
Colin Fitz
1997
Other Voices
2000
Getting to Know You
1999
East of A
2000