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).
42 movies · 35 shows
Vicious
2025·6.0
National Memorial Day Concert
2023·2.0
Unpregnant
2020·6.9
Still Laugh-In: The Stars Celebrate
2019·5.3
Treehouse
2019·5.5
Drone
2017·5.3
Alien Code
2017·5.4
The Crash
2017·4.5
An American Girl Story: Maryellen 1955 - Extraordinary Christmas
2016·7.8
A Country Called Home
2016·5.3
Scooby-Doo! WrestleMania Mystery
2014·7.3
Escape from Polygamy
2013·6.7
Should've Been Romeo
2012·4.3
The Unprofessional
2012·0.0
1408
2007·6.7
For Your Consideration
2006·5.8
Right at Your Door
2006·5.9
Madison
2005·5.8
Dickie Roberts: Former Child Star
2003·5.1
Full Frontal
2002·4.6
World Traveler
2002·4.1
K-PAX
2001·7.2
High Heels and Low Lifes
2001·6.2
BigLove
2001·7.5
East of A
2000·10.0
Gun Shy
2000·5.2
The Broken Hearts Club: A Romantic Comedy
2000·6.3
Other Voices
2000·4.0
The Big Tease
1999·5.9
Mystery, Alaska
1999·6.3
True Crime
1999·6.5
Harvest
1999·4.3
Getting to Know You
1999·7.6
The Alarmist
1998·4.5
54
1998·5.9
Deep Impact
1998·6.2
Murder One: Diary of a Serial Killer
1997·7.0
Fathers' Day
1997·5.5
Private Parts
1997·6.5
Colin Fitz
1997·6.3
Backfire!
1995·3.6
Miracle on 34th Street
1994·6.8