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).
Filmography
Cast Credits
Vicious
Character:
MOVIE • 2025
National Memorial Day Concert
Character: Self
MOVIE • 2023
Heels
Character: Willie Day
TV • 2021
Unpregnant
Character: Debra Clarke
MOVIE • 2020
The L Word: Generation Q
Character: Anne Finley
TV • 2019
Still Laugh-In: The Stars Celebrate
Character: Self
MOVIE • 2019
Treehouse
Character: Lilith
MOVIE • 2019
The Kids Are Alright
Character: Peggy Cleary
TV • 2018
25 Words or Less
Character: Self
TV • 2018
For The People
Character: Chloe Daniels
TV • 2018
Will & Grace
Character: Janet
TV • 2017
Drone
Character: Ellen
MOVIE • 2017
Loaded
Character: Casey
TV • 2017
Alien Code
Character: Rebecca
MOVIE • 2017
The Crash
Character: Sarah Schwab
MOVIE • 2017
An American Girl Story: Maryellen 1955 - Extraordinary Christmas
Character: Kay Larkin
MOVIE • 2016
Divorce
Character: Kathy DeSantis
TV • 2016
Match Game
Character: Self - Panelist
TV • 2016
To Tell the Truth
Character: Self - Panelist
TV • 2016
Chelsea
Character: Self
TV • 2016