Cast & creator
Mark Harmon
Best known for The Late Show with Stephen Colbert, The Tonight Show Starring Johnny Carson, Family Guy
Thomas Mark Harmon (born September 2, 1951) is an American actor, producer and director. He is known for playing the lead role of Leroy Jethro Gibbs on NCIS (2003-2021), a role which has earned him six nominations at the People's Choice Awards including a win for Favorite TV Crime Drama Actor in 2017. Since 2008, he has also been a producer and executive producer of the show as well as its' spinoff series NCIS: New Orleans. His character of NCIS special agent Leroy Jethro Gibbs was introduced in a guest starring role in two episodes of JAG, and continued on the spinoff show NCIS. He had a recurring role as Secret Service special agent Simon Donovan in a four-episode story arc in The West Wing in 2002, for which he received an Emmy Award nomination. One of his first national TV appearances (other than as an athlete) was in a commercial for Kellogg's Product 19 cereal with his father, Tom Harmon, its longstanding TV spokesman. Thanks to his sister Kristin's in-laws, Ozzie and Harriet Nelson, he landed his first job as an actor in an episode of Ozzie's Girls. He has been starring in television and film since the mid-1970s, after a career as a collegiate football player with the UCLA Bruins. He's been married to actress Pam Dawber since 1987 and they have 2 sons. His son, actor Sean Harmon, had a recurring role as a young Leeroy Jethro Gibbs on NCIS.
Also known as: Thomas Mark Harmon
49
film credits
62
television credits
104
1944–2025 · acting roles
6.6
average across scored titles
Signature credits
Known for
Across film & television
Filmography (111)
Showing 111 of 111 credits
The Late Show with Stephen Colbert
Self - Guest
2015
The Tonight Show Starring Johnny Carson
Self
1962
Family Guy
Leroy Jethro Gibbs (voice)
1999
The Kelly Clarkson Show
Self
2019
NCIS
Leroy Jethro Gibbs
2003NCIS
Executive Producer
2003
Saturday Night Live
Self - Host
1975
The View
Self
1997
The Late Late Show with James Corden
Self
2015
Jimmy Kimmel Live!
Self
2003
JAG
Leroy Jethro Gibbs
1995
The West Wing
Simon Donovan
1999
Chicago Hope
Jack McNeil
1994Chicago Hope
Director
1994
The Tonight Show with Jay Leno
1992
The Love Boat
Doug Bradbury
1977
Golden Globe Awards
Self - Nominee
1944Golden Globe Awards
Self
1944
Adam-12
Officer Gus Corbin
1968
St. Elsewhere
Robert Caldwell
1982
NCIS: New Orleans
Leroy Jethro Gibbs
2014NCIS: New Orleans
Executive Producer
2014
Emergency!
Ofcr. Dave Gordon
1972
Boston Public
Director
2000The Tony Danza Show
Self
2004
Moonlighting
Sam Crawford
1985
Police Woman
Stanski
1974Police Woman
Paul Donin
1974
Laverne & Shirley
1976
NCIS: Origins
Older Leroy Jethro Gibbs (voice) (uncredited)
2024NCIS: Origins
Older Leroy Jethro Gibbs (uncredited)
2024NCIS: Origins
Older Leroy Jethro Gibbs
2024NCIS: Origins
Executive Producer
2024
The Bonnie Hunt Show
Self
2008
The Megan Mullally Show
Self - Guest
2006
Steve Harvey
Self
2012
From the Earth to the Moon
Wally Schirra
1998
Freaky Friday
Ryan
2003
The Legend of Tarzan
Bob Markham (voice)
2001
The Hardy Boys / Nancy Drew Mysteries
1977
The Arsenio Hall Show
Self
2013
Entertainment Tonight
Self
1981
Freakier Friday
Ryan
2025
Natural Born Killers
Mickey Knox in TV
1994
The Rosie O'Donnell Show
Self
1996
Centennial
Captain John McIntosh
1978
Fear and Loathing in Las Vegas
Magazine Reporter
1998
Reasonable Doubts
Det. Dicky Cobb
1991
Charlie Grace
Charlie Grace
1995Charlie Grace
Producer
1995
Delvecchio
Ronnie Striker
1976
Flamingo Road
Field Carlyle
1981
Strangers
Mark
1996
240-Robert
Thib Thibideaux
1979
Harts of the West
1993
Hallmark Hall of Fame
Charles
1951
Wyatt Earp
Sheriff Johnny Behan
1994
The American West
Self
2016
Justice League: Crisis on Two Earths
Superman (voice)
2010
Goliath Awaits
Peter Cabot
1981
All's Fair
1976
Chasing Liberty
James Foster
2004
Joe Montana: Cool Under Pressure
Self - Narrator (voice)
2022
The Deliberate Stranger
Ted Bundy
1986
Summer School
Freddy Shoop
1987
The Dream Merchants
Johnny Edge
1980
Stealing Home
Billy Wyatt
1988
And Never Let Her Go
Thomas Capano
2001
The Presidio
Jay Austin
1988
The Last Supper
Dominant Male
1995
Beyond the Poseidon Adventure
Larry Simpson
1979
Magic in the Water
Jack Black
1995
Weather Girl
Dale
2009
Comes a Horseman
Billy Joe Meynert
1978
Crossfire Trail
Bruce Barkow
2001
Let's Get Harry
Harry
1986
All or Nothing: The Michigan Wolverines
Narrator (voice)
2018
Cold Heaven
Alex Davenport
1992
Local Boys
Jim Wesley
2002
The Deliberate Stranger
Ted Bundy
1986
Sam
Mike Breen
1978
NCISverse: The First 1,000
Self
2024
Prince of Bel Air
Robin Prince
1986Ozzie's Girls
1973
I'll Remember April
John Cooper
1999
Dear America: Letters Home from Vietnam
(voice)
1987
Sweet Bird of Youth
Chance Wayne
1989
Dillinger
John Dillinger
1991
And Never Let Her Go
Thomas Capano
2001
Little Mo
Norman Brinker
1978Shadow of a Doubt
Charles Spencer
1991
After the Promise
Elmer Jackson
1987
Worth Winning
Taylor Worth
1989
Casualties
Tommy Nance
1997
The First to Go
Jeremy Hampton
1997
Certain Prey
Lucas Davenport
2011Certain Prey
Executive Producer
2011Eleanor and Franklin: The White House Years
Robert Dunlap
1977
Tuareg: Desert Warrior
Gacel Sayah
1984
Flamingo Road
Fielding Carlyle
1980
Till There Was You
Frank Flynn
1991
Getting Married
Howie Lesser
1978
For All Time
Charles Lattimer
2000
Fourth Story
David Shepard
1991Intimate Portrait: Pam Dawber
Self
2002
Sonic Boom
Student Controller
1974
Long Road Home
Ertie Robertson
1991
The Amati Girls
Lawrence
2001
The Wild
Self
2019
Intimate Agony
Tommy
1983
Original Sins
Johnathan Franye
1995