Mary McCormack

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

Law & Order

Watch What Happens Live with Andy Cohen

Law & Order: Criminal Intent

ER

The West Wing

The Pitt

Scandal

The Late Late Show with Craig Ferguson

All Movies (42)

• Vicious2025 · as Mother
• National Memorial Day Concert2023 · as Self
• Unpregnant2020 · as Debra Clarke
• Still Laugh-In: The Stars Celebrate2019 · as Self
• Treehouse2019 · as Lilith
• Drone2017 · as Ellen
• Alien Code2017 · as Rebecca
• The Crash2017 · as Sarah Schwab
• An American Girl Story: Maryellen 1955 - Extraordinary Christmas2016 · as Kay Larkin
• A Country Called Home2016 · as Amanda
• Scooby-Doo! WrestleMania Mystery2014 · as Ms. Richards (voice)
• Escape from Polygamy2013 · as Leann
• Should've Been Romeo2012 · as Ellen
• The Unprofessional2012 · as Hilary Pfeiffer-Dunne
• 14082007 · as Lilly Enslin
• For Your Consideration2006 · as Pilgrim Woman
• Right at Your Door2006 · as Lexi
• Madison2005 · as Bonnie McCormick
• Dickie Roberts: Former Child Star2003 · as Grace Finney
• Full Frontal2002 · as Linda
• World Traveler2002 · as Margaret
• K-PAX2001 · as Rachel Powell
• High Heels and Low Lifes2001 · as Frances
• BigLove2001 · as Phoebe
• East of A2000 · as Daphne
• Gun Shy2000 · as Gloria Nesstra
• The Broken Hearts Club: A Romantic Comedy2000 · as Anne
• Other Voices2000 · as Anna
• The Big Tease1999 · as Monique
• Mystery, Alaska1999 · as Donna Biebe
• True Crime1999 · as Michelle Ziegler
• Harvest1999 · as Agent Becka Anslinger
• Getting to Know You1999 · as Leila Lee
• The Alarmist1998 · as Sally
• 541998 · as New Year's Eve Wife (uncredited)
• Deep Impact1998 · as Andrea Baker
• Murder One: Diary of a Serial Killer1997 · as Justine Appleton
• Fathers' Day1997 · as Virginia Farrell (uncredited)
• Private Parts1997 · as Alison Stern
• Colin Fitz1997 · as Moira
• Backfire!1995 · as Sarah
• Miracle on 34th Street1994 · as Myrna Foy

All TV Shows (37)

• The Pitt2025 · as Dr. Linda Conley
• Heels2021 · as Willie Day
• The L Word: Generation Q2019 · as Anne Finley
• The Kids Are Alright2018 · as Peggy Cleary
• 25 Words or Less2018 · as Self
• 25 Words or Less2018
• 25 Words or Less2018 · as Mary McCormack
• For the People2018 · as Chloe Daniels
• Will & Grace2017 · as Janet
• Loaded2017 · as Casey
• Divorce2016 · as Kathy DeSantis
• Match Game2016 · as Self - Panelist
• To Tell the Truth2016 · as Self - Panelist
• Chelsea2016 · as Self
• Chelsea Does2016 · as Herself
• Angie Tribeca2016 · as Abigail Liukin
• Welcome to the Family2013 · as Caroline Yoder
• The Newsroom2012 · as Molly Levy
• Scandal2012 · as Lisa Elliot
• House of Lies2012 · as Denna Altshuler
• Watch What Happens Live with Andy Cohen2009 · as Self - Guest
• Late Night with Jimmy Fallon2009 · as Self
• In Plain Sight2008 · as Mary Shannon
• The Late Late Show with Craig Ferguson2005 · as Self
• Traffic2004 · as Carole McKay
• K Street2003 · as Maggie Morris
• The Ellen DeGeneres Show2003 · as Self
• Jimmy Kimmel Live!2003 · as Self
• Law & Order: Criminal Intent2001 · as Mary Shannon
• The West Wing1999 · as Kate Harper
• The Late Late Show with Craig Kilborn1999 · as Self - Guest
• Murder One1995 · as Justine Appleton
• The Wright Verdicts1995 · as Beth Eckhart
• ER1994 · as Debbie
• The Tonight Show with Jay Leno1992
• Law & Order1990 · as Rickie the Bartender
• Tony Awards1956 · as Self - Nominee