Mark Harmon

Biography

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.

Known For

NCIS

Family Guy

The Late Show with Stephen Colbert

The Tonight Show Starring Johnny Carson

The Kelly Clarkson Show

Saturday Night Live

JAG

The West Wing

All Movies (48)

• Freakier Friday2025 · as Ryan
• NCISverse: The First 1,0002024 · as Self
• The Wild2019 · as Self
• Certain Prey2011 · as Lucas Davenport
• Justice League: Crisis on Two Earths2010 · as Superman (voice)
• Weather Girl2009 · as Dale
• Chasing Liberty2004 · as James Foster
• Freaky Friday2003 · as Ryan
• Local Boys2002 · as Jim Wesley
• Intimate Portrait: Pam Dawber2002 · as Self
• And Never Let Her Go2001 · as Thomas Capano
• Crossfire Trail2001 · as Bruce Barkow
• The Amati Girls2001 · as Lawrence
• For All Time2000 · as Charles Lattimer
• I'll Remember April1999 · as John Cooper
• Fear and Loathing in Las Vegas1998 · as Magazine Reporter
• Casualties1997 · as Tommy Nance
• The First to Go1997 · as Jeremy Hampton
• The Last Supper1995 · as Dominant Male
• Magic in the Water1995 · as Jack Black
• Original Sins1995 · as Johnathan Franye
• Natural Born Killers1994 · as Mickey Knox in TV
• Wyatt Earp1994 · as Sheriff Johnny Behan
• Cold Heaven1992 · as Alex Davenport
• Till There Was You1991 · as Frank Flynn
• Shadow of a Doubt1991 · as Charles Spencer
• Long Road Home1991 · as Ertie Robertson
• Fourth Story1991 · as David Shepard
• Dillinger1991 · as John Dillinger
• Worth Winning1989 · as Taylor Worth
• Sweet Bird of Youth1989 · as Chance Wayne
• Stealing Home1988 · as Billy Wyatt
• The Presidio1988 · as Jay Austin
• After the Promise1987 · as Elmer Jackson
• Dear America: Letters Home from Vietnam1987 · as (voice)
• Summer School1987 · as Mr. Freddy Shoop
• Let's Get Harry1986 · as Harry
• The Deliberate Stranger1986 · as Ted Bundy
• Prince of Bel Air1986 · as Robin Prince
• Tuareg: Desert Warrior1984 · as Gacel Sayah
• Intimate Agony1983 · as Tommy
• Flamingo Road1980 · as Fielding Carlyle
• Beyond the Poseidon Adventure1979 · as Larry Simpson
• Comes a Horseman1978 · as Billy Joe Meynert
• Little Mo1978 · as Norman Brinker
• Getting Married1978 · as Howie Lesser
• Eleanor and Franklin: The White House Years1977 · as Robert Dunlap
• Sonic Boom1974 · as Student Controller

All TV Shows (54)

• NCIS: Origins2024 · as Older Leroy Jethro Gibbs (voice) (uncredited)
• NCIS: Origins2024 · as Older Leroy Jethro Gibbs (uncredited)
• Joe Montana: Cool Under Pressure2022 · as Self - Narrator (voice)
• The Kelly Clarkson Show2019 · as Self
• All or Nothing: The Michigan Wolverines2018 · as Narrator (voice)
• The American West2016 · as Self
• The Late Show with Stephen Colbert2015 · as Self - Guest
• The Late Late Show with James Corden2015 · as Self
• NCIS: New Orleans2014 · as Leroy Jethro Gibbs
• The Arsenio Hall Show2013 · as Self
• The Bonnie Hunt Show2008 · as Self
• The Megan Mullally Show2006 · as Self - Guest
• The Tony Danza Show2004 · as Self
• NCIS2003 · as Leroy Jethro Gibbs
• Jimmy Kimmel Live!2003 · as Self
• The Legend of Tarzan2001 · as Bob Markham (voice)
• And Never Let Her Go2001 · as Thomas Capano
• The West Wing1999 · as Simon Donovan
• Family Guy1999 · as Leroy Jethro Gibbs (voice)
• From the Earth to the Moon1998 · as Wally Schirra
• The View1997 · as Self
• The Rosie O'Donnell Show1996 · as Self
• Strangers1996 · as Mark
• JAG1995 · as Leroy Jethro Gibbs
• Charlie Grace1995 · as Charlie Grace
• Chicago Hope1994 · as Jack McNeil
• Harts of the West1993
• The Tonight Show with Jay Leno1992
• Reasonable Doubts1991 · as Det. Dicky Cobb
• The Deliberate Stranger1986 · as Ted Bundy
• Moonlighting1985 · as Sam Crawford
• St. Elsewhere1982 · as Robert Caldwell
• Goliath Awaits1981 · as Peter Cabot
• Entertainment Tonight1981 · as Self
• Flamingo Road1981 · as Field Carlyle
• The Dream Merchants1980 · as Johnny Edge
• 240-Robert1979 · as Thib Thibideaux
• Centennial1978 · as Captain John McIntosh
• Sam1978 · as Mike Breen
• The Love Boat1977 · as Doug Bradbury
• The Hardy Boys / Nancy Drew Mysteries1977
• All's Fair1976
• Delvecchio1976 · as Ronnie Striker
• Laverne & Shirley1976
• Saturday Night Live1975 · as Self - Host
• Police Woman1974 · as Stanski
• Police Woman1974 · as Paul Donin
• Ozzie's Girls1973
• Emergency!1972 · as Ofcr. Dave Gordon
• Adam-121968 · as Officer Gus Corbin
• The Tonight Show Starring Johnny Carson1962 · as Self
• Hallmark Hall of Fame1951 · as Charles
• Golden Globe Awards1944 · as Self - Nominee
• Golden Globe Awards1944 · as Self