| Year | Title | Role | Notes |
| 1975–1978 | Sorting it Out | Host | (Local Chicago show) Won 3 Regional Emmy Awards |
| 1978 | That Thing on ABC | Performer | Variety special |
| The Love Boat | Heather McKenzie | Episode: "Memories of You/Computerman/Parlez Vous?" |
| 1979 | The Dooley Brothers | Lucy Bennett | Unaired pilot |
| Young Guy Christian | Mia Mishugi |
| The Cracker Factory | Cara | Television film |
| Family | Joan Phillips | Episode: "Sleeping Over" |
| Trapper John, M.D. | Lauren | Episode: "The Shattered Image" |
| 1980 | The Promise of Love | Lorraine Simpson | Television film |
| M*A*S*H | Lt. Mendenhall | Episode: "Bottle Fatigue" |
| 1981 | The Princess and the Cabbie | Carol | Television film |
| Ghost of a Chance | Jenny Clifford | Unaired pilot |
| 1982–1987, 1993 | Cheers | Diane Chambers | Primetime Emmy Award for Outstanding Lead Actress in a Comedy Series (1983) Golden Globe Award for Best Actress – Television Series Musical or Comedy (1985) Golden Globe Award for Best Supporting Actress – Series, Miniseries or Television Film (1983) TV Land Awards (2006–2007) Viewers for Quality Television Award (1985–1986) Nominated – American Comedy Award for Funniest Female Performer in a Television Series (1987) Nominated – Primetime Emmy Award for Outstanding Lead Actress in a Comedy Series (1984–1986) Nominated – Primetime Emmy Award for Outstanding Guest Actress in a Comedy Series (1993) Nominated – Golden Globe Award for Best Actress – Television Series Musical or Comedy (1984) Nominated – People's Choice Award for Favorite Female TV Performer (1984–1985) |
| 1990 | Voices Within: The Lives of Truddi Chase | Truddi Chase | Television film |
| 1991 | The Real Story of... | The Dame | Voice, episode: "Baa Baa Black Sheep" |
| Memories of M*A*S*H | Host | Documentary |
| 1992 | Fatal Memories | Eileen Franklin Lipsker | Television film |
| A Message from Holly | Kate |
| 1993–1994 | Good Advice | Susan DeRuzza | 19 episodes |
| 1993 | Basic Values: Sex, Shock & Censorship in the 90's [sic] | Fay Sommerfield | Television film |
| 1995 | Lois & Clark: The New Adventures of Superman | Lucille Newtrich/Ultra Lucille | Episode: "Ultra Woman" |
| Welcome to Paradise | Anne | Television film |
| Freaky Friday | Ellen Andrews |
| 1996 | A Different Kind of Christmas | Elizabeth Gates |
| Susie Q | Penny Sands |
| 1995, 1996 | Murphy Brown | Dottie Wilcox | 2 episodes |
| 1996, 2001 | Frasier | Diane Chambers | 3 episodes Nominated – Primetime Emmy Award for Outstanding Guest Actress in a Comedy Series (1996) |
| 1996 | Life with Louie | Sally Tubbs | Voice, episode: "A Fair to Remember" |
| Boston Common | Louise Holmes | Episode: "Trustee and Sympathy" |
| 1998 | Sabrina the Teenage Witch | The Wicked Witch | Episode: "Sabrina and the Beanstalk" |
| Kelly Kelly | Kelly Novack | 7 episodes; also co-executive producer |
| Diagnosis: Murder | Kay Ludlow | Episode: "Write, She Murdered" |
| 1999 | Vanished Without a Trace | Elizabeth Porterson | Television film |
| Chicken Soup for the Soul | Teacher | Episode: "The Green Boots" |
| 2000 | Beggars and Choosers | Pamela Marston | Episode: "Fasten Your Seatbelts" |
| 2002 | The Brady Bunch in the White House | Carol Brady | Television film |
| The Santa Trap | Molly Emerson |
| 2003 | 8 Simple Rules | Mary Ellen Doyle | Episode: "The Doyle Wedding" |
| Strong Medicine | Lauren Chase | Episode: "Jeaneology" |
| 2004 | Joan of Arcadia | Miss Candy | Episode: "Vanity, Thy Name Is Human" |
| 2005 | Boston Legal | Miriam Watson | Episode: "Death Be Not Proud" |
| Yes, Dear | Margaret | Episode: "The New Neighbors" |
| Complete Savages | Judy | 2 episodes |
| 2006 | Falling in Love with the Girl Next Door | Betsy Lucas | Television film |
| Honeymoon with Mom | Marla |
| 2009 | Ice Dreams | Harriet Clayton |
| 2009–2018 | Modern Family | DeDe Pritchett | 8 episodes Nominated – Gold Derby Awards for Comedy Guest Actress (2010) Nominated – OFTA Television Award for Best Guest Actress in a Comedy Series (2011) |
| 2010 | Family Guy | Carol Brady | Voice, episode: "Excellence in Broadcasting" |
| 2011 | Holiday Engagement | Meredith Burns | Television film |
