He/she was in THAT?

David Janssen appeared in three Francis movies as well as Bonzo Goes to College .

Johnny Depp is briefly shown in Platoon; Steve Buscemi plays Buddy Holly the waiter in Pulp Fiction; and in Apocalypse Now! there is a really young Lawrence Fishburne.

You already amended this to First Blood, but David Caruso was also in The King of New York, along with Laurence Fishburne and Wesley Snipes.

Jim Carrey was also in Earth Girls Are Easy.

Two actors who played henchmen in the James Bond movies, Harold Sakata (Oddjob) and Richard Kiel (Jaws), also appeared in episodes of Gilligan’s Island.

Oh, really?

Please read your wiki before you post.

Liam Neeson was also in High Spirits

My apologies. You’re correct.

So is Dom DeLuise (much more recognizable, as the sergeant who tells the Soviets how to get past the USA’s air-to-air missiles).

Robin Williams was in Can I Do It 'Til I Need Glasses?, which, apparently, was a sequel to a movie titled, If You Do It, You’ll Go Blind. Actually, Williams’s role was cut the first time the movie was released, but it was re-released with his part in it after Mork & Mindy made him popular (and he tried to stop the re-release when the advertising mentioned his part in the film).

Sean Penn, Tom Cruise, and Earl Hindman (Wilson from Home Improvement) were in Taps (which starred George C. Scott and Timothy Hutton).

Bill Paxton was in the music video “Fish Heads” which was sung by a band called Barnes and Barnes, which contained Bill Mumy.

Cliff from Cheers is in one of the Star Wars movies (original trilogy)

Nathan Fillion was in Blast from the Past.

Jim Carrey was in Once Bitten, as was Lauren Hutton.

Oops double post.

He was also in Peggy Sue Got Married. So were Joan Allen and Sofia Coppola.

Fishburn lied about his age to be in that. He had to be at least 17, but he was only 15.

Oscar from The Office appeared briefly in The Italian Job - he was the security guard at the gate to Edward Norton’s house.

Remember the terrible movie Mercury Rising? The one with the autistic kid who broke the NSA encryption code in a puzzle magazine and had to be resuced by Bruce Willis? One of the programmers had a nerd girlfriend, who was played by Carrie Preston, the redhead waitress from True Blood.

Another one I’ve mentioned before in these threads: the preacher from Hot Fuzz? (“Oh, fuck off, grasshopper!”) Belloq from Raiders of the Lost Ark.

You’re probably thinking of the 1964 version of Fail-Safe; a serious take on the same sort of story as Dr. Strangelove.

If memory serves, Patrick Stewart had small supporting roles in both Dune and Excalibur, before he starred in STNG.

Bill Paxton was also in Pat Benatar’s Shadows of the Night video along with Judge Frickin’ Reinhold.

Everyone had small supporting roles in Dune:

Francesca Annis (who I only mention because she was also in Krull. ** Súil Dubh** - I stand corrected on Liam Neeson.)
Brad Dourif
Linda Hunt
Freddie Jones
Virginia Madsen
Jürgen Prochnow
Patrick Stewart
Sting
Dean Stockwell
Max von Sydow
Alicia Witt
Sean Young

Heather Graham played Mercedes in License to Drive.

Edited because I was a day late and a dollar short.

Something that struck me as really odd recently…Fiona and Steve on Showtime’s Shameless starred opposite each other in Dragonball Evolution.