What Oscar have had regular roles on sitcoms?

Dame Judi Dench
Tom Hanks
Catherine Zeta-Jones

Tom Hanks........

Donna Reed
Shirley Jones
Cloris Leachman
Helen Hunt
Mary Tyler Moore (nominated)

Ron Howard
Walter Brennan
Bing Crosby
Fred McMurray(nominated)
Barbara Stanwyck

Shirley Booth
Michael Douglas
Red Buttons
Robin Williams

Marisa Tomei on A Differnet World and James Dunn on It's a Great Life.

Hailey Mills

Estelle Parsons
Jack Albertson
Ernest Borgnine
Goldie Hawn

There has been lots of them:

Geena Davis - Buffalo Bill, Sara, The Geena Davis Show
Art Carney - The Honeymooners
Mercedes Ruehl - Frasier
Julie Andrews - Julie
Richard Dreyfuss - Karen
Jack Lemmon - Heaven For Betsy, That Wonderful Guy
Eileen Heckart - Annie McGuire, The 5 Mrs Buchanans, Out of the Blue
George C. Scott - Mr. President
Patty Duke - The Patty Duke Show
Geroge Burns - The Burns & Allen Show
Ray Milland - The Ray Milland Show
Martin Balsam - Archie Bunker's Place
Lee Grant - Fay
Halle Berry - Living Dolls
Jodie Foster - Paper Moon, Bob & Carol, Ted & Alice
Hillary Swank - Camp Wilder
Sally Field - Gidget, The Flying Nun
Celeste Holm - Honestly Celeste
Shirley MacLaine - Shirley's World
Jessica Tandy - The Marriage
Faye Dunaway - It Had To Be You
Rita Moreno - 9 to 5
Ellen Burstyn - The Ellen Burstyn Show