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