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Mary McCormack

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

2025
Vicious

as Mother

Movie
2007
1408

as Lilly Enslin

Movie
2001
K-PAX

as Rachel Powell

Movie
1999
Mystery, Alaska

as Donna Biebe

Movie
1998
Deep Impact

as Andrea Baker

Movie
1994
Miracle on 34th Street

as Myrna Foy

Movie
1999
The West Wing

as Kate Harper

TV Show