Police procedural television shows such as CSI and NCIS have been attracting well-known actors and celebrities for years, with their cameos and guest appearances either happening towards the start of their eventually successful careers or once they are already established.

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NCIS alone has had so many notable guest appearances that it can be hard to keep track of all of them, with there being some surprisingly big names that get lost in the shuffle. The cameo characters that are played by these actors and celebrities often have interesting interactions with Agent Gibbs, NCIS' overall main character.

10 Sean Astin Appeared As Investigator Tyler Elliott

NCIS Sean Astin Elliott

Sean Astin's most iconic roles have arguably been Samwise Gamgee in The Lord Of The Rings movies, and Mikey in The Goonies, but he has more recently featured in the likes of Stranger Things, Brooklyn Nine-Nine, and NCIS.

In 2012, he appeared in NCIS: Naval Crime Investigative Service's Season 9, as no-nonsense investigator Tyler Elliott, a far cry from the roles that he is best known for.

9 Michelle Obama's Work With "Joining Forces" Was Shown In NCIS' Thirteenth Season

NCIS Michelle Obama

Michelle Obama has appeared in the likes of Parks and Recreation and Black-ish over the years as herself, drawing mass media presence with every appearance.

In 2016 while she was still the First Lady, she appeared in NCIS' episode "Homefront," with her promoting her charity "Joining Forces," an organization devoted to helping and supporting service members, veterans, and their families. The scene that showed Michelle Obama thanking Gibbs for his work, was actually filmed in the White House, making NCIS the first dramatic production to do so at the time.

8 Colin Hanks Played An Inspector Determined To Bring Gibbs Down

NCIS Colin Hanks

The eldest son of the iconic actor Tom Hanks, Colin Hanks, has also done well for himself with a vast number of roles over the years, including the likes of Fargo, Dexter, and the reboot Jumanji movies.

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In 2013, Colin appeared in three episodes of NCIS, spanning both the end of the tenth season and the beginning of the eleventh, as Inspector Richard Parsons, who went after Gibbs in an attempt to get him arrested and dismantle the NCIS. He was successful and the rest of the NCIS team resigned.

7 Abigail Breslin Played A Blind Little Girl

arnold-schwarzenegger and abigail-breslin in maggie

Abigail Breslin is known for more recent roles in movies like Zombieland: Double Tap and Maggie, and television series Scream Queens, but before all of this, she was a talented child actress, appearing in the likes of Little Miss Sunshine and NCIS.

She appeared in NCIS at the beginning of the second season in "See No Evil" as a blind young girl named Sandy Watson who was kidnapped along with her mother, with a plot subsequently revealing that the father was behind the events.

6 Jim Rash Appeared As A Doctor

captain-america-easter-egg-community-jim-rash

Jim Nash is best known for his hilarious role as the eccentric Dean Pelton in the beloved series Community, but has established himself as a talented Oscar-winning screenwriter, director, and comedic actor with countless other projects over the years.

He appeared in the tenth episode of NCIS's first season titled "Left For Dead," as Dr. Joel Sanderson, a doctor treating an amnesiac patient that couldn't recall some vital information about a potential bomb threat.

5 Millie Bobby Brown Was Troubled Girl Rachel

NCIS Millie Bobby Brown

Millie Bobby Brown really burst onto the scene in 2016 with her captivating performances as Eleven in the mysterious television series Stranger Things, but the English actress had already appeared in big shows prior with the likes of NCIS: Naval Criminal Investigative Service.

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In 2014, she appeared in "Parental Guidance Suggested" as Rachel Barnes, a troubled young girl who killed her mother as she believed it would help to encourage her Navy SEAL father to come home to her. This was an early glimpse into Millie Bobby Brown's exceptional range and ability to put across a terrifying persona even as a 10-year-old.

4 Sterling K. Brown Played A Killer Clown

NCIS Sterling K Brown

Sterling K. Brown is one of those actors who are instantly recognizable. He has played a whole host of different roles over the years, from Randall Pearson in This is Us to Erik Killmonger's father N'Jobu in Black Panther. He even appeared in one of Brooklyn Nine-Nine's most iconic episodes as a charismatic murderer, showing off his sinister acting skills just as he had previously done in his 2013 NCIS appearance.

He played Elijah Banner in "Devil's Triad," Season 11's tenth episode. He was a killer clown that shot a Marine and kidnapped Gibbs and Fornell's ex-wives, as well as Fornell's daughter.

3 Jamie Lee Curtis Appeared As Gibbs' Former Girlfriend

NCIS Jamie Lee Curtis Dr Ryan

Jamie Lee Curtis has had an impressive career spanning back to 1977, with her starring in the likes of A Fish Called Wanda and Halloween, as well as appearing in episodes of ArcherNew Girl, and many more.

In 2012, she joined the ranks of NCIS for five episodes, as Dr. Samantha Ryan, head of the DOD PsyOps Division and a former girlfriend of Special Agent Leroy Jethro Gibbs.

2 Billy Dee Williams Played Gibbs' Namesake Leroy Jethro Moore

Billy Dee Williams

Billy Dee Williams is instantly recognizable and best known for his iconic performances as Lando Calrissian in the Star Wars universe, with his roles spanning several movies and video games within the franchise. Outside of Star Wars, he has had a long and storied career, stretching back to 1959.

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In 2012, he appeared in NCIS: Naval Criminal Investigative Service as Leroy Jethro Moore, Agent Gibbs' namesake. In the episode "The Namesake" it was revealed that Gibbs was named Leroy Jethro after his father's best friend, Billy Dee Williams' character. Williams then reprised the role once again in 2014, when Gibbs' father had passed away, with several returning characters, including Moore attending the funeral.

1 Zac Efron Appeared On An Episode Just Before His High School Musical Debut

Zac Efron spins a ball on his finger in High School Musical

Zac Efron's role as Troy Bolton in High School Musical is arguably what catapulted him to the famous status and fortune that he now finds himself at, but just three days before that debut, he appeared in an episode of NCIS.

This 2006 episode of NCIS's third season titled "Deception," saw Efron play Daniel Austin, a teenager who bought a phone from a Navy Commander. While this was a rather minor role, Efron joined the NCIS alum of celebrities and famous actors, with the CSI series boasting a similarly impressive roster of past famous appearances.

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