The daughter of radio personality Jim O'Brien, Gilpin began her performing career on his show. She studied theater at the Dallas Theatre Center, where Chantal Westerman, later a "Good Morning America" show business correspondent, was house manager. After college, she attended the British-American Academy in London. When she returned to the US, she worked as a make-up artist in Dallas, before deciding to pursue acting. The novice landed an apprenticeship at the Williamstown Theatre Festival which led to regional theater and off-off-Broadway productions. In the late 1980s, Gilpin relocated to L.A. and began her TV career. She eventually appeared in guest spots on series including "Matlock," "Designing Women," "Wings," "Cheers" and as a regular on the short-lived 1991 series "Flesh and Blood." While "Frasier" remains the actress most well-known role, she has also appeared in the telepics "Fight for Justice: The Nancy Conn Story" (1995), "The Secret She Carried" (1996) and "Laughter on the 23rd Floor" (2001), as well as in the feature films "Spring Forward" (1999), "How to Kill Your Neighbor's Dog" (2000).
In addition to her film and television roles, Gilpin spent several years as the distinctively smoky radio voice behind a long-running series of ads for Wells Fargo, and she also can be heard as characters in such projects as the animated series "The Lionhearts," "Hercules," "Superman," "Justice League," "King of the Hill" and the CGI film "Final Fantasy: The Spirits Within" (2001).