Stephnie Weir was born in Odessa, Texas. She attended Odessa College where she majored in theater and broadcasting. Weir then transferred to Southern Illinois University at Edwardsville, where she majored in anthropology and women's studies. After moving to Chicago, Stephnie Weir began performing at the Improv Olympic and later on The Second City's main stage and the Goodman Theatre. Weir teamed up with her husband, Robert Dassie, to form the comedy duo WeirDass.
Weir joined the cast of MADtv in 2000 as a feature performer, for the 6th season. However, she was later promoted to a repertory performer status the following season.
Weir left MADtv in January 2006, midway through her 6th season of the show. Weir had announced in 2005 (season 10) that she would be leaving. However, fellow cast members Aries Spears and Paul Vogt would leave as well, and Ron Pederson would be let go by Fox due to budget cuts, so in order for the viewers to feel a sense of continuity, Weir was persuaded to stay on the show until half way through season 11. Some of her famous characters included Angela Wright, Dr. Kylie, Dorothy Lanier, Leona Campbell and Dot Goddard.
- The Other Side of the Tracks
- Eden Court
- Fun with Dick and Jane (2005)
- New Port South
- Too Much Flesh
- On Becoming Blonde
- My Blood doesn't clot right
- Ping Pong Playa
- 50 First Dates