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.

Filmografía destacada

• Freakier Friday (2025)
• NCIS: Origins (2024)
• NCIS: Origins (2024)
• NCISverse: The First 1,000 (2024)
• Joe Montana: Cool Under Pressure (2022)
• The Kelly Clarkson Show (2019)
• The Wild (2019)
• All or Nothing: The Michigan Wolverines (2018)
• The American West (2016)
• The Late Late Show with James Corden (2015)
• NCIS: New Orleans (2014)
• The Arsenio Hall Show (2013)
• Certain Prey (2011)
• Justice League: Crisis on Two Earths (2010)
• Weather Girl (2009)
• The Bonnie Hunt Show (2008)
• The Megan Mullally Show (2006)
• The Tony Danza Show (2004)
• Chasing Liberty (2004)
• NCIS (2003)
• Freaky Friday (2003)
• Jimmy Kimmel Live! (2003)
• Local Boys (2002)
• Intimate Portrait: Pam Dawber (2002)
• The Legend of Tarzan (2001)
• And Never Let Her Go (2001)
• And Never Let Her Go (2001)
• Crossfire Trail (2001)
• The Amati Girls (2001)
• For All Time (2000)