this thread is on so-called tv actors and actresses, who started playing supporting characters in sitcoms, dramas etc, and later on became the main stars of their own shows. for example:

tony danza- taxi and who's the boss?
johnny galecki- roseanne and the big bang theory
raven simone- the cosby show and that's so raven?

John Ritter - supporting on The Walton's, starring on Three's Company and 8 Simple Rules

Marla Gibbs - supporting on The Jeffersons, starring on 227

Robert Guillaume - supporting on Soap, starring on Benson

Mary Tyler Moore - supporting on Dick Van Dyke, starring on MTM

Kelsey Grammer - supporting on Cheers, starring on Frasier and Back To You.

Kirsty Alley - suporting on Cheers, starring on Veronica's Closet and Fat Actress.

Scott Baio - supporting on Happy Days, starring in Joanie Loves Chachi and Charles In Charge.

Valerie Harper from The Mary Tyler Moore Show to Rhoda & The Hogan Family

Cloris Leachman from the MTM show to Phyllis

Ed Asner from the MTM show to the Lou Grant Show

Betty White from the MTM show to the Golden Girls

Ted Knight from the MTM show to Too Close For Comfort

Gavin Macleod from the MTM show to the Love Boat

Abe Vigoda went from Barney Miller to Fish

Brad Garrett from Everybody Loves Raymond to Til Death

Bob Denver Maynard from Dobie Gillis To Gilligan's Island

Audra Lindley and Norman Fell from Three's Company to The Ropers.

Linda Lavin from Det. Wentworth on Barney Miller to Alice.

Valerie Harper from Rhoda on Mary Tyler Moore to Rhoda to Valerie.

Sarah Chalke Becky #2 on Roseanne to Scrubs.

Sally Struthers (All in the Family, Gloria)
Jim Nabors (Andy Griffith Show, Gomer Pyle)
Pernell Roberts (Bonanza, Trapper John)
Michael Landon (Bonanza, Little House on the Prairie, Highway to Heaven)
Ken Berry (F Troop, Mayberry RFD)
Dennis Weaver (Gunsmoke, Gentle Ben, McCloud)
Don Adams (The Bill Dana Show, Get Smart)
Richard Crenna (The Real McCoys, Slattery's People)
Kathy Nolan (The Real McCoys, Broadside)
Lee Majors (Big Valley, Men from Shiloh, Six Million Dollar Man, Fall Guy)

Richard Crenna (The Real McCoys, Slattery's People)

and It Takes Two (with Patty Duke, Helen Hunt and Anthony Edwards)

Valerie Harper from The Mary Tyler Moore Show to Rhoda & The Hogan Family

Cloris Leachman from the MTM show to Phyllis

Ed Asner from the MTM show to the Lou Grant Show

Betty White from the MTM show to the Golden Girls

Ted Knight from the MTM show to Too Close For Comfort

Gavin Macleod from the MTM show to the Love Boat

Boy, you pretty much covered the entire cast of Mary Tyler Moore-LOL

Yeah lol! I forgot Gordy though.

John Amos as Gordy on MTM to James Evans on Good Times

John Larroquette - Night Court (Dan Fielding) to the John Larroquette Show (John Hemingway).

Yeah lol! I forgot Gordy though.

John Amos as Gordy on MTM to James Evans on Good Times

I stand corrected :lol:

Micheal J fox played in family ties then he started playing in spin city.

He was also the star of "Family Ties" though.

And you guys have forgotten about JoMarie Payton as Harriet Winslow, supporting in "Perfect strangers", lead in "Family Matters".

OK I dont know all real names so some maybe the character name:

Sherman Hemsley - All In The Family/Jeffersons
Florida Evans - Maude/Good Times
Horation - NYPD Blue/CSI Miami (the red headed guy)
Lisa Bonet - TCS/A Different World
Mama - Carol Burnet Show/Mama Family
Julia Louis Dryfus - SNL/Day By Day/Seinfeld
Courtney Cox - Family Ties/Friends
Brian Austin Green - Knots Landing/90210

John Ritter - supporting on The Waltons, star of Three's Company, Three's a Crowd, Hooperman (his only drama that he got star billing on), and 8 Simple Rules

Richard Mulligan - supporting on Soap, starring on Empty Nest

Jason Bateman - supporting on Silver Spoons, starring on It's Your Move, Valerie/The Hogan Family, and Arrested Development

Howard Hesseman - semi-supporting on WKRP in Cincinnati, starring on Head of the Class

Tim Reid - semi-supporting on WKRP in Cincinnati, supproting on Simon & Simon, star on Sister, Sister

Michael Landon - Bonanza/Little House on the Prairie/Highway to Heaven

Lorne Greene - Bonanza, supporting on Battlestar Galatica/Galatica 1980

Wiilie Aames - supporting on Eight is Enough, starring Charles in Charge

Conrad Bain - supporting on Maude, star on Diff'rent Strokes

Rue McClanahan - supporting on Maude and Mama's Family, star on The Golden Girls

Cloris Leachman - MTM/Phyllis/The Facts of Life

Esther Rolle - Maude/Good Times

Isabel Sanford - All in the Family/The Jeffersons

Dennis Franz - supporting/semi-supporting on Hill Street Blues, star on Beverly Hills Buntz and on NYPD Blue

Henry Winkler moved from fifth to third to second to first billing on Happy Days.

Tim Reid - semi-supporting on WKRP in Cincinnati, supproting on Simon & Simon, star on Sister, Sister

Don't forget that he was the star of Frank's Place as well

Robert Fuller - Supporting in Wagon Train , Lead in Laramie & Emergency!

Burt Reynolds - Supporting in Gunsmoke , Lead in Dan August & Evening Shade