After graduating from Juilliard in 1974, the Buffalo native began her stage career in a Baltimore production of "She Stoops to Conquer" (1976). She made her Broadway debut in "Hide and Seek" (1980), and worked steadily thereafter, nabbing an OBIE for her performance in "A Midsummer Night's Dream" in 1983. In addition to earning two Tonys, Baranski also won the Drama Desk Award twice ("The Real Thing"; and for her turn as a neurotic suburbanite in "Lips Together, Teeth Apart", 1991) and was hilarious as Bunny Flingus in John Guare's "The House of Blue Leaves" (1986, shown on PBS in 1987). On the debit side, she appeared in the epic flop musical "Nick and Nora" (1991), but she received raves in 1997 when she headlined the Encores! presentation of "Promises, Promises" with Martin Short at Manhattan's City Center and in 1999 when she co-starred as Mrs. Lovett opposite Kelsey Grammer's Demon Barber of Fleet Street in five performances of "Sweeney Todd" as part of L.A.'s Reprise! musical concert series.

Opting to try her hand at movie acting in the early 80s, Baranski made her feature film debut with a bit part in "Soup for One" (1982), then played a nymphomaniac in Marshall Brickman's uneven romantic comedy "Lovesick" (1983). She gained attention as a man-eating meter maid in "Crackers" (1984), Louis Malle's remake of "Big Deal on Madonna Street", and followed up with small roles in several films with high-recognition quotients (e.g., "9 1/2 Weeks" and "Legal Eagles", both 1986). The supporting role of Andrea Reynolds, the new woman in the life of suspected wife killer Claus von Bulow in Barbet Schroeder's "Reversal of Fortune" (1990) finally got Baranski some quality on-screen time. She made other noteworthy appearances in "Addams Family Values" (1993) as the giddy counselor who runs a summer camp, "The Ref" (1994) as Kevin Spacey's snooty sister-in-law, and "Jeffrey" (1995) as the society matron sponsoring a hoe-down for AIDS. She next appeared in "The Birdcage" (1996) as the absent mother of the boy she and Robin Williams conceived and Williams then raised with his tender-hearted drag queen lover, played by Nathan Lane. She was the philandering wife of Warren Beatty's suicidal senator in "Bulworth" (1998), had a memorable cameo as an author of child-rearing books whose own daughter is up to no good in "Cruel Intentions" (1999), the teen remake of "Dangerous Liaisons", and gave a delightful turn as a never-was/has-been actress in the sharply written comedy "Bowfinger" (1999) opposite Steve Martin and Eddie Murphy. 2000 saw Baranski hold her own against yet another comic genius--Jim Carey--playing the title character's childhood sweetheart in the live-action version of the Dr. Seuss classic "How the Grinch Stole Christmas". In 2002 the actress took a small but pivitol role in the big-screen version of the hit stage musical "Chicago," playing the sob-sister journalist Mary Sunshine (a role typically played on the stage by a man in drag), and returned to the screen in 2003 in the Hollywood/Bollywood satire "The Guru."

The actress made her TV-movie debut in "Playing For Time" (CBS, 1980) about a troupe of concentration camp detainees who play music to distract their captors. She guested on the series "Law & Order" (NBC) and played opposite Hume Cronyn and Jessica Tandy in the CBS movie "To Dance With the White Dog" (1993). Baranski returned to series TV in 2000 with the CBS sitcom "Welcome to New York", which she executive produced and starred in as the scheming producer of morning TV program.