
Marg Helgenberger
Biography
Mary Marg Helgenberger (born November 16, 1958) is an American actress. She began her career in the early 1980s and first came to attention for playing the role of Siobhan Ryan on the daytime soap opera Ryan's Hope from 1982 to 1986. She is best known for her role as Catherine Willows in the CBS police procedural drama CSI: Crime Scene Investigation (2000–13) and the subsequent TV movie Immortality (2015). She reprised the role in the sequel CSI: Vegas (2022–present). Helgenberger is also known for playing the role of K.C. Koloski in the ABC drama China Beach (1988–91), which earned her the 1990 Emmy Award for Outstanding Supporting Actress in a Drama Series. She is also known for roles in the TV series Under the Dome and Intelligence, and the films Species (1995), Species II (1998), Erin Brockovich (2000), and Mr. Brooks (2007).…
Filmography

This Week
1981 · 9.0

A Dog's Journey
2019 · 8.1

Peacemaker
1989 · 8.0

Tales from the Crypt
1989 · 8.0

ER
1994 · 7.8

The Larry Sanders Show
1992 · 7.8

Frasier
1993 · 7.7

CSI: Vegas
2021 · 7.7

CSI: Crime Scene Investigation
2000 · 7.6

Inflammable
1995 · 7.5

Erin Brockovich
2000 · 7.4

King of the Hill
1997 · 7.4

All Rise
2019 · 7.4

China Beach
1988 · 7.4

CSI: Immortality
2015 · 7.2

Wonder Woman
2009 · 7.2

Under the Dome
2013 · 7.1

Matlock
1986 · 7.0

Boston Blue
2025 · 7.0

Mr. Brooks
2007 · 6.9

Spenser: For Hire
1985 · 6.9

Bad Boys
1995 · 6.8

American Playhouse
1982 · 6.6

Fallen Angels
1993 · 6.6

Intelligence
2014 · 6.5
Shell Game
1987 · 6.5

Murder Live!
1997 · 6.4

Almost Friends
2017 · 6.3

thirtysomething
1987 · 6.3

Giving Up the Ghost
1998 · 6.3

Always
1989 · 6.2

In Good Company
2004 · 6.1

My Fellow Americans
1996 · 6.1

Death Dreams
1991 · 6.1

Species
1995 · 6.0

The Hidden Room
1991 · 6.0

Distant Cousins
1993 · 6.0

Where Are My Children?
1994 · 5.9

Gold Coast
1997 · 5.8

Lethal Vows
1999 · 5.8

Fire Down Below
1997 · 5.7

The Cowboy Way
1994 · 5.7

After Midnight
1989 · 5.7

Perfect Murder, Perfect Town: JonBenét and the City of Boulder
2000 · 5.7

Conundrum
1996 · 5.7

Crooked Hearts
1991 · 5.6

The Tommyknockers
1993 · 5.6

Blind Vengeance
1990 · 5.5

Species II
1998 · 5.2

Happy Face Murders
1999 · 5.2

The Last Time I Committed Suicide
1997 · 5.1

Columbus Day
2008 · 5.0

Thanks of a Grateful Nation
1998 · 4.8

Keys
1994 · 4.5

Just Looking
1995 · 4.3

Lie Down with Lions
1994 · 4.1

In Sickness and in Health
1992 · 4.0

When Love Kills: The Seduction of John Hearn
1993 · 3.2

Perfect Murder, Perfect Town
2000 · 0.0

China Beach: Pilot
1988 · 0.0