Lets list the guest apperances on sitcoms by future celebirties. I am only talking about guest appearnce. Not recurring role or regular on a series. Like Lenardo Di Capreo on Growing Pains or George Cloney on Facts of Life. Also you can't count Janet Jackson's apperances on Good Times, Diff'rent Strokes and Fame for the same reason I just described and the fact that she was already famous when she appered on those shows. She was famous the moment the Jackson 5 became famous. If not at least when she made apperances with her brothers on talk shows and variety shows, for example Diana Shore, Cher, The Jackson variety show.

Here is my starting list. I will add more latter.

Hallie Barry (A Diffenent World)
Britney Murphy (Sister Sister)
Flex Alexander (Sister Sister)
Robin Givens (the Cosby show and Diff'rent Strokes)
Gary Coleman (the Jeffersons)
Michael Richards (Night Court and Cheers)
Jason Alexander (Newhart)
James Avery (Newhart)
Tatyana Ali (the Cosby show)
Alicia Keys (the Cosby show)

The following unknowns at the time appeared on the Partridge Family. Cheryl Ladd, Farrah Fawcett, Tony Geary, Mark Hamill, Lou Gossett Jr., Richard Pryor, and Jaclyn Smith. Charles Grodin also appeared on the Bob Newhart episode of Captain Nice.

Tom Hanks on "Taxi"
Tom Hanks on "Happy Days
Jack Knickolson (I know I spelled that wrong) on "The Andy Griffith show"
Shelley Long on "MASH"
Ted Danson on "Taxi"
George Wednt on "Taxi"
Rhea Pearlman on "Taxi"
Rob Reiner on "The Partridge Family"
Rob Reiner on "The Beverly Hillbilies"
Buddy Ebsen on "The Andy Griffith show"
Jamie Farr on "The Dick Van Dyke show"
Jamie Farr on "F Troop"
Jerry Van Dyke on "The Mary Tyler Moore show"

Loni Anderson "Three's Company"
Joanna Kerns "Three's Company"
Alicia Keys "Cosby Show"

Tom Hanks--The Love Boat

Angela Bassett - The Cosby Show
Kathy Bates - The Love Boat
Tom Selleck - Taxi
Martin Short - Taxi
Henry Winkler - The Mary Tyler Moore Show
Cheryl Ladd - Happy Days
Marion Ross - The Brady Bunch
Erin Moran - My Three Sons
Gavin MacLeod - The Dick Van Dyke Show
Barbara Eden - I Love Lucy
Patrick Swayze - M*A*S*H

Brad Pitt - Head of the Class
Adam Sandler - The Cosby Show
Helen Hunt - The Facts of Life
John Ritter - The Mary Tyler Moore Show

I don't want to sound mean. But what did I say about Janet Jackson. She does not count because she was already famous, though not as famous as would latter become but still famous and it was a recurring character.

Jack Klugman on "The Twilight Zone"
Barbera Eden on "The Andy Griffith show"
Marlo Thomas on "McHales Navy"
Jamie Farr on "The Dick Van Dyke show"

Taking a bit of a risk here, my first post on this board is something I'm not totally sure about!

Didn't Robin Williams play "Mork" in an episode of 'Happy Days', before 'Mork & Mindy' began?

Nice to be here. :wave:

yes, he did. That was the episode that first introduced Mork. I remember reading somewhere once, when that show aired, that Gary Marshalls son (Gary Marshall created both shows) was a fan of either "Star Wars" or "star Trek, I forget which, and he asked his father to put a space alien in an episode of "Happy Days":wave:

Pamela Anderson - Happy Days
LeeLee Sorbieski - NewsRadio
John Mahoney - Cheers
Fred Willard - Get Smart
Tom Bosley - Get Smart

Lisa Kudrow-"Cheers"

Peri Gilpin (Roz on "Fraiser")-"Cheers"

Doris Roberts, Helen Hunt and Isabel Sanford - The Mary Tyler Moore show

Kristen

Joanna Kearns - "Three's Company"
Anne Schedeen - "Three's Company"
Loni Anderson - "Three's Company"
Brad Pitt - "Head of the Class"
Penny Marshall - "The Mary Tyler Moore Show"

Jodie Foster and Robert Guilliame (sp?) - "Julia"

A few that come to mind:

John Ritter on "Mary Tyler Moore" (He played the minister that
married Ted and Georgette in Mary's apartment).

Jay Leno on "Laverne and Shirley"

Tom Selleck on "Taxi"

Barbara Eden on "I Love Lucy" (possibly her first TV appearance)

Clint Eastwood on "Mr. Ed" (he played himself)

Several people appeared on "The Andy Griffith Show" early in their careers:

Barbara Eden (she played a manicurist)

Bill Bixby (Played the son of a rich man who was jailed by Andy
for a hit and run accident)

Jack Nicholson (Played a man falsely acussed of breaking into a
store)

Jay Leno on "One Day at a Time"
Jackie Gleason in "The Life of Riley" for all you old-timers! (the show was in 1949!!!)

And, no, that apperance on "I Love Lucy" by Barbera Eden wasn't her first TV appearence. She had previously been one of the stars of a short-lived series called "How to Marry a Millionaire" which was based on a movie w/Marilyn Monroe. (she played the Monroe role)

Originally posted by Jimbo
Several people appeared on "The Andy Griffith Show" early in their careers:

Barbara Eden (she played a manicurist)

Bill Bixby (Played the son of a rich man who was jailed by Andy
for a hit and run accident)

Jack Nicholson (Played a man falsely acussed of breaking into a
store)

Also:

Alan Hale, Jr.

Allan Melvin (several, including some bad guy roles)

Originally posted by Jimbo
A few that come to mind:

Also worth mentioning:

Alley Mills on The Waltons

also, there was: Bob Denver on "The Andy Griffith show"

Gavin McLeod on "The Andy Griffith show"
Richard Dawson on "The Dick Van Dyke show"
Richard Dreyffus on "Bewitched"