Mark Harmon is an American actor, producer and former college football player best known for playing Leroy Jethro Gibbs on NCIS. Born on September 2, 1951, in Burbank, California, Harmon turned 75 years old in September 2026. He has been married to actress Pam Dawber since 1987, and they have two sons, Sean and Ty. Although Harmon stepped away from NCIS as a regular star in 2021, his Gibbs story is far from over: CBS announced that he will appear throughout Season 3 of NCIS: Origins in a new present-day storyline.
Mark Harmon Quick Bio
| Detail | Information |
|---|---|
| Full Name | Thomas Mark Harmon |
| Professional Name | Mark Harmon |
| Date of Birth | September 2, 1951 |
| Age in 2026 | 75 |
| Birthplace | Burbank, California |
| Nationality | American |
| Profession | Actor, producer, director, author |
| Famous Role | Leroy Jethro Gibbs |
| Major Series | NCIS, NCIS: Origins, St. Elsewhere |
| Wife | Pam Dawber |
| Marriage Date | March 21, 1987 |
| Children | Sean Harmon and Ty Harmon |
| Father | Tom Harmon |
| Mother | Elyse Knox |
| College | UCLA |
| Former Sport | College football |
| Current NCIS Work | NCIS: Origins |
| 2026 Book | Ghosts of Sicily |
| Net Worth | Exact personal figure not publicly verified |
Who Is Mark Harmon?
Mark Harmon is one of television’s most familiar faces.
For almost two decades, millions of viewers knew him as Gibbs, the quiet NCIS team leader famous for his rules, intense stare and habit of trusting instinct more than technology.
Yet Harmon had already built a long acting career before NCIS premiered.
His professional credits stretch back to the 1970s, and his résumé includes medical dramas, romantic roles, comedies and feature films. IMDb identifies him as an actor, producer and director with dozens of credits beyond Gibbs.
What makes Harmon unusual is how little he seems interested in behaving like a typical celebrity.
He has spent decades on television but keeps his private family life remarkably quiet.
How Old Is Mark Harmon?
Mark Harmon was born on September 2, 1951, in Burbank, California.
He turned 75 years old on September 2, 2026.
His full birth name is Thomas Mark Harmon.
That means he was already 51 when NCIS premiered in 2003.
Instead of slowing down, the show gave him the role that ultimately defined the biggest part of his career.
Mark Harmon Came From a Famous Family
Entertainment and sports were already part of Mark’s childhood.
His father, Tom Harmon, was a famous football player and sports broadcaster.
His mother, Elyse Knox, was an actress and artist.
Mark also has two sisters, Kelly Harmon and the late Kristin Nelson.
The family therefore lived around both sports and entertainment.
Mark could easily have followed either path.
For a while, he chose football.
Mark Harmon Played College Football
Before Gibbs carried a federal badge, Mark Harmon was a quarterback.
He played college football for UCLA, becoming the Bruins’ starting quarterback during the early 1970s.
That athletic background appears to have helped shape the calm physical confidence that later became part of his acting style.
Harmon has rarely played characters who seem nervous about entering a room.
Even when Gibbs said nothing, viewers could usually tell who was in charge.
Mark Harmon Did Not Immediately Become an Actor
Acting was not Mark’s first clear career plan.
In a 2026 interview, Harmon explained that he had worked in advertising as a merchandising director but felt uncertain about what he actually wanted to do.
He eventually explored acting, made contact with producer Jack Webb’s company and began receiving opportunities in television.
His early appearances included programs such as Adam-12, Police Woman and Laverne & Shirley.
The road to NCIS was still decades away.
Mark Harmon in St. Elsewhere
One of Harmon’s important early dramatic roles came in St. Elsewhere.
He played Dr. Robert Caldwell.
The medical drama gave him more serious material and helped show that he could do much more than rely on the good looks that had attracted early attention. IMDb specifically highlights the role as one of the performances that helped establish him as a serious television actor.
That career flexibility became important.
Harmon could play romantic.
He could play funny.
He could play serious.
And later he could play Gibbs.
Mark Harmon Was Once Named Sexiest Man Alive
Before becoming known as the silver-haired leader of NCIS, Harmon was considered one of television’s major heartthrobs.
People named him Sexiest Man Alive in 1986.
That was around the same period he met the woman who would become his wife.
Interestingly, Harmon’s personal life after that point became much less dramatic than the celebrity title might suggest.
He did not build a reputation for constant public relationships.
Instead, he married Pam Dawber and stayed married.
Who Is Mark Harmon’s Wife?
Mark Harmon’s wife is actress Pam Dawber.
Dawber became famous as Mindy McConnell opposite Robin Williams in the sitcom Mork & Mindy, which ran from 1978 to 1982. She later starred in My Sister Sam.
Mark and Pam met at a friend’s party in 1986.
They married the following year.
From the beginning, both were careful about keeping their relationship out of the press. Dawber told People in 1987 that they did not want their private life completely exploited by publicity.
That approach never really changed.
When Did Mark Harmon and Pam Dawber Marry?
Mark and Pam married on March 21, 1987.
IMDb continues to list the marriage as active and confirms they have two children together.
That means the couple have now been married for more than 39 years.
Their 40th wedding anniversary will arrive in March 2027.
In Hollywood terms, that is an exceptionally long marriage.
Why Is Their Marriage So Private?
Harmon has said privacy is simply part of who they are.
He explained in a previous interview that he and Pam stay home a lot and that neither they nor their sons are particularly interested in turning life into social-media content.
That is probably why there are fewer personal stories about Mark Harmon than fans might expect after such a long television career.
The family appears publicly when it makes sense.
They simply do not treat everyday life as entertainment.
Mark Harmon and Pam Dawber Have Two Sons
Mark and Pam have two sons, Sean Harmon and Ty Christian Harmon.
People’s 2025 look at the NCIS cast families identifies Sean as an actor and stunt performer and Ty as a screenwriter.
Neither son became a celebrity on the same scale as his parents.
But both entered creative work.
And Sean has a particularly interesting connection with his father’s most famous role.
Who Is Sean Harmon?
Sean Harmon is Mark and Pam’s older son.
He has worked as an actor and stunt performer.
NCIS fans may already recognize him without realizing who he is.
Sean appeared on the original series as a younger version of Leroy Jethro Gibbs.
That casting made perfect sense.
Instead of searching for an actor who looked vaguely like Mark Harmon, the production had his real son available.
Why Didn’t Sean Harmon Star in NCIS: Origins?
When CBS created NCIS: Origins, Sean did not return as young Gibbs.
Austin Stowell received the leading role instead.
People reported that Sean chose to work behind the scenes as an executive producer rather than reprise his old part.
That means father and son remain connected with the series in a new way.
Mark narrates and produces.
Sean helps produce.
Austin Stowell plays young Gibbs.
Who Is Ty Harmon?
Ty Christian Harmon is Mark and Pam’s younger son.
Unlike Sean, Ty has generally stayed away from acting.
People identifies him as a screenwriter.
He keeps an especially low public profile.
That fits the wider Harmon family pattern.
The family works around entertainment, but they do not appear interested in making every personal detail public.
Mark Harmon Became Leroy Jethro Gibbs
Everything changed professionally when Harmon began playing Leroy Jethro Gibbs.
Gibbs first appeared through JAG before becoming the central character of NCIS when the series launched in 2003.
Harmon eventually appeared in hundreds of episodes.
IMDb credits him with more than 400 NCIS appearances across the long-running series.
Gibbs became known for his numbered rules, Marine background, woodworking, coffee and intense loyalty to his team.
But the character worked because Harmon rarely overplayed him.
Gibbs did not need to shout every five minutes.
How Successful Is NCIS?
Extremely successful.
CBS currently lists the original NCIS as having 23 seasons, with Season 23 airing through May 2026.
The show also created a much larger franchise.
Over the years, that universe expanded into multiple spinoffs and international versions.
Very few television roles last long enough for the original actor to watch an entire television universe grow around the character.
Harmon did.
Why Did Mark Harmon Leave NCIS?
Harmon stepped away from regular NCIS duty in 2021.
Gibbs chose to stay in Alaska rather than return to his former life.
That ending allowed the actor to leave without killing the character.
It also left the door open.
People notes that Harmon continued to remain involved with the franchise even after leaving the original show as its regular lead.
That decision now looks important.
Gibbs is returning again.
What Is NCIS: Origins?
NCIS: Origins is a prequel about Gibbs’ early years.
CBS says the series follows a young Gibbs in the early 1990s as he begins working at the Camp Pendleton office under Mike Franks. Austin Stowell plays young Gibbs, while Mark Harmon narrates the story.
The show premiered in October 2024.
Season 2 finished in May 2026.
At first, older Gibbs was mostly a narrator.
Season 3 is changing that.
Is Mark Harmon Returning as Gibbs in 2026?
Yes, and the return is bigger than a single cameo.
CBS announced in June 2026 that Harmon would appear as older Gibbs throughout Season 3 of NCIS: Origins. People reported that the present-day Gibbs storyline will run across all episodes of the season.
The story is expected to connect present-day Gibbs with events from his younger years at Camp Pendleton.
That is a major shift.
Older Gibbs is no longer simply a voice telling us what happened.
He is becoming part of the action again.
Why Is the Gibbs Return Important?
Fans had wondered for years whether Harmon would ever truly return to the role.
He had already made limited appearances connected with Origins.
But a season-long story is something different.
It tells viewers that Gibbs’ life after Alaska still matters.
It also allows NCIS: Origins to operate on two timelines.
Young Gibbs can show how events began.
Older Gibbs can show why those memories still matter decades later.
For longtime fans, that creates a direct bridge between the old series and the prequel.
Mark Harmon Is Also an Author
Acting is no longer Harmon’s only major project.
He has collaborated with retired NCIS special agent Leon Carroll Jr. on nonfiction books about real naval intelligence history.
Their 2026 release is Ghosts of Sicily: The True Story of the Naval Intelligence Agents Who Courted the Mob to Fight Nazis in America and the Battlefields of Italy.
People reported that the book was released on April 14, 2026.
The story examines how U.S. naval intelligence interacted with organized-crime figures during World War II.
That may sound completely different from television.
But it still connects with Harmon’s long interest in naval investigative history.
Why Does Mark Harmon Write With Leon Carroll Jr.?
Carroll spent many years as an NCIS technical adviser.
That real-world experience helped NCIS understand how the agency operates.
Harmon and Carroll eventually turned that relationship into nonfiction writing.
Their books explore historical naval intelligence rather than fictional Gibbs cases.
It is an interesting career development.
After pretending to be an NCIS agent for years, Harmon began helping tell stories about real intelligence work.
Mark Harmon Returned in Freakier Friday
Harmon also returned to one of his well-known movie roles in Freakier Friday in 2025.
IMDb lists him again as Ryan, the character he first played in the 2003 Freaky Friday alongside Jamie Lee Curtis and Lindsay Lohan.
That gave Harmon another return to a familiar character just as his Gibbs story was becoming active again.
It seems retirement has not really become his style.
Mark Harmon Once Worked as a Carpenter
Harmon has spoken warmly about working as a carpenter.
IMDb preserves a quote in which he compared acting with carpentry because both could make him excited to wake up and go to work, knowing that every day would involve something different.
That detail fits his public personality.
He does not usually speak about acting as fame.
He tends to talk about it as work.
Gibbs’ famous love of building boats by hand suddenly feels very appropriate.
Mark Harmon Once Helped Rescue Two Teenagers
One of Harmon’s best-known real-life stories happened outside his home.
IMDb recounts that a car crashed and caught fire nearby. Harmon used a sledgehammer to break the vehicle’s window and helped pull two teenage boys out while Pam called emergency services.
Harmon later downplayed his role.
That reaction became part of why fans liked the story.
It sounded strangely similar to something Gibbs might do: deal with the problem first and avoid talking about it afterward.
Mark Harmon’s Net Worth
Mark Harmon has earned substantial money during a long television career.
IMDb reports that his NCIS salary reached $500,000 per episode for Season 9.
But exact net-worth figures published by celebrity-finance sites should still be treated as estimates.
Real net worth requires knowledge of investments, taxes, property, producer income, debts and other financial details that are not completely public.
It is safe to say Harmon has had a highly successful career.
It is less safe to claim one exact fortune as proven fact.
What Is Mark Harmon Doing in 2026?
Mark Harmon is surprisingly busy at 75.
He released Ghosts of Sicily with Leon Carroll Jr. in April.
He remains involved with NCIS: Origins.
And CBS has announced a much larger Gibbs role for Season 3, with Harmon appearing throughout the season instead of remaining only a narrator.
That means 2026 is not simply a year of looking back at Mark Harmon’s career.
It is a year in which he is actively adding to it.
Final Thoughts
Mark Harmon has had one of television’s most durable careers.
He began as a college quarterback.
He tried advertising.
Then acting took over.
Roles in series such as St. Elsewhere helped establish him, while movies including Summer School and Freaky Friday expanded his audience.
Then came Gibbs.
From 2003 onward, NCIS made Harmon one of the most recognizable actors on television.
He eventually stepped away from regular episodes, but he never completely left the franchise.
Today, NCIS: Origins tells young Gibbs’ story while Harmon narrates from the future. CBS has now gone even further, bringing older Gibbs into a season-long storyline for Season 3.
His private life has been remarkably steady too.
He has been married to Pam Dawber since 1987, and they raised two sons, Sean and Ty, while deliberately keeping family life away from constant publicity.
At 75, Harmon could easily spend his time celebrating old achievements.
Instead, he is writing books, producing television and returning to Gibbs.
That is why Mark Harmon remains more than a former NCIS star.
He is still part of the story.
FAQs About Mark Harmon
How old is Mark Harmon in 2026?
Mark Harmon was born on September 2, 1951. He turned 75 in September 2026.
What is Mark Harmon’s full name?
His full name is Thomas Mark Harmon.
Where was Mark Harmon born?
He was born in Burbank, California.
Who is Mark Harmon’s wife?
He is married to actress Pam Dawber, best known for Mork & Mindy.
When did Mark Harmon marry Pam Dawber?
They married on March 21, 1987.
Are Mark Harmon and Pam Dawber still married?
Yes. They remain married in 2026.
How many children does Mark Harmon have?
Mark and Pam have two sons, Sean and Ty Harmon.
Did Mark Harmon’s son play Gibbs?
Yes. Sean Harmon appeared as a younger Gibbs on NCIS.
What does Ty Harmon do?
Ty Harmon has worked as a screenwriter.
Did Mark Harmon play football?
Yes. Before acting, he played college football at UCLA.
What is Mark Harmon best known for?
He is best known for playing Leroy Jethro Gibbs on NCIS.
When did Mark Harmon leave NCIS?
He stepped away as a regular cast member in 2021.
Is Mark Harmon returning to NCIS?
He is returning as older Gibbs throughout Season 3 of NCIS: Origins.
Who plays young Gibbs in NCIS: Origins?
Austin Stowell plays the younger version of Gibbs.
Does Mark Harmon narrate NCIS: Origins?
Yes. CBS confirms that NCIS: Origins is narrated by Mark Harmon.
Is Mark Harmon still acting?
Yes. His announced NCIS: Origins Season 3 storyline puts him back on screen as Gibbs in 2026.
Did Mark Harmon write a book?
Yes. His 2026 book with Leon Carroll Jr. is Ghosts of Sicily, released on April 14, 2026.
Was Mark Harmon in Freakier Friday?
Yes. He returned as Ryan in the 2025 sequel.
What is Mark Harmon’s net worth?
His exact personal net worth is not publicly verified. Online figures should be treated as estimates.
What is Mark Harmon doing now?
He is writing nonfiction books, producing and appearing in NCIS: Origins, and preparing for a larger Gibbs storyline in Season 3.
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