Mark Harmon
- Teen actor
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.
Acted in
Freakier Friday
2025
as Ryan
NCIS: Origins
2024
as Older Leroy Jethro Gibbs (uncredited)
NCIS: Origins
2024
as Older Leroy Jethro Gibbs (voice) (uncredited)
NCISverse: The First 1,000
2024
as Self
Joe Montana: Cool Under Pressure
2022
as Narrator (voice)
The Wild
2019
as Self
All or Nothing: The Michigan Wolverines
2018
as Narrator (voice)
The American West
2016
as Self
NCIS: New Orleans
2014
as Leroy Jethro Gibbs
Certain Prey
2011
as Lucas Davenport
Justice League: Crisis on Two Earths
2010
as Clark Kent / Superman (voice)
Weather Girl
2009
as Dale
Chasing Liberty
2004
as James Foster
NCIS
2003
as Leroy Jethro Gibbs
Freaky Friday
2003
as Ryan
Local Boys
2002
as Jim Wesley
Intimate Portrait: Pam Dawber
2002
as Self
The Legend of Tarzan
2001
as Bob Markham (voice)
And Never Let Her Go
2001
as Thomas Capano
And Never Let Her Go
2001
as Thomas Capano
Crossfire Trail
2001
as Bruce Barkow
The Amati Girls
2001
as Lawrence
For All Time
2000
as Charles Lattimer
The West Wing
1999
as Simon Donovan
I'll Remember April
1999
as John Cooper
Family Guy
1999
as Leroy Jethro Gibbs (voice)
Fear and Loathing in Las Vegas
1998
as Magazine Reporter
From the Earth to the Moon
1998
as Wally Schirra
Casualties
1997
as Tommy Nance
The First to Go
1997
as Jeremy Hampton
JAG
1995
as Leroy Jethro Gibbs
Charlie Grace
1995
as Charlie Grace
The Last Supper
1995
as Dominant Male
Magic in the Water
1995
as Jack Black
Original Sins
1995
as Johnathan Franye
Chicago Hope
1994
as Jack McNeil
Natural Born Killers
1994
as Mickey Knox in TV
Wyatt Earp
1994
as Sheriff Johnny Behan
Harts of the West
1993
Cold Heaven
1992
as Alex Davenport
Reasonable Doubts
1991
as Det. Dicky Cobb
Till There Was You
1991
as Frank Flynn
Shadow of a Doubt
1991
as Charles Spencer
Long Road Home
1991
as Ertie Robertson
Fourth Story
1991
as David Shepard
Dillinger
1991
as John Dillinger
Worth Winning
1989
as Taylor Worth
Sweet Bird of Youth
1989
as Chance Wayne
Stealing Home
1988
as Billy Wyatt
The Presidio
1988
as Jay Austin
After the Promise
1987
as Elmer Jackson
Dear America: Letters Home from Vietnam
1987
as (voice)
Summer School
1987
as Mr. Freddy Shoop
Let's Get Harry
1986
as Harry
The Deliberate Stranger
1986
as Ted Bundy
Prince of Bel Air
1986
as Robin Prince
Moonlighting
1985
as Sam Crawford
Tuareg: Desert Warrior
1984
as Gacel Sayah
Intimate Agony
1983
as Tommy
St. Elsewhere
1982
as Robert Caldwell
Goliath Awaits
1981
as Peter Cabot
Flamingo Road
1981
Flamingo Road
1980
as Fielding Carlyle
The Dream Merchants
1980
as Johnny Edge
240-Robert
1979
as Thib Thibideaux
Beyond the Poseidon Adventure
1979
as Larry Simpson
Comes a Horseman
1978
as Billy Joe Meynert
Centennial
1978
as Captain John McIntosh
Little Mo
1978
as Norman Brinker
Getting Married
1978
as Howie Lesser
Sam
1978
as Mike Breen
The Love Boat
1977
as Doug Bradbury
Eleanor and Franklin: The White House Years
1977
as Robert Dunlap
The Hardy Boys / Nancy Drew Mysteries
1977
All's Fair
1976
Delvecchio
1976
as Ronnie Striker
Laverne & Shirley
1976
Police Woman
1974
Police Woman
1974
as Stanski
Sonic Boom
1974
as Student Controller
Ozzie's Girls
1973
Emergency!
1972
Adam-12
1968
as Officer Gus Corbin
Hallmark Hall of Fame
1951
as Charles