Kate Walsh was born in San Jose, California. Her mother, Angela Bocchetto is of Italian descent, with roots from Potenza, in the Southern Italian region of Basilicata.
Walsh graduated from Catalina Magnet High School and studied acting at the University of Arizona before dropping out. Walsh moved to New York City and joined a comedy troupe, Burn Manhattan, supporting herself by waitressing.
Before modeling, Walsh worked at Burger King and Dairy Queen. She began as a model in Japan in the 1980s where she also taught English. Later, she moved to Chicago and worked with the Piven Theatre Workshop. She performed on National Public Radio in the production of the radio play Born Guilty.
After playing Cathy Buxton in the Homicide: Life on the Street episode “Stakeout” in 1996 and Navy Lieutenant Kirstin Blair in the Law & Order episode “Navy Blues”, Walsh’s first major television appearance was in 1997, when she appeared on The Drew Carey Show as Drew Carey’s love interest, Nicki Fifer. She wore a fatsuit in some episodes of the show, as the Nicki character was a formerly obese woman who lost weight and slowly started to gain it back.
Walsh went on to portray Carol Nelson in HBO’s The Mind of the Married Man television series, and played Norm Macdonald’s romantic interest in the sitcom The Norm Show. She made a guest appearance on CSI: Crime Scene Investigation as Mimosa, a transgender woman. She sometimes appeared in sketches on Late Night with Conan O’Brien.
Walsh had a recurring role on Karen Sisco as Detective Marley Novak in 2003 and 2004. In 2005, she was cast in her breakout role in the ABC series Grey’s Anatomy, as Dr. Addison Montgomery, the estranged spouse of Derek Shepherd (“Dr. McDreamy”, played by Patrick Dempsey).
In February 2007, Walsh’s Grey’s Anatomy character received a spin-off of Grey’s Anatomy that began airing in September 2007. Taye Diggs, Tim Daly, Amy Brenneman, Chris Lowell, and Audra McDonald were cast in the spin-off, Private Practice. Walsh would return for six episodes across the fourth through eighth seasons of Grey’s Anatomy, including the musical episode “Song Beneath the Song”.
In 2013, Walsh appeared in Full Circle, a 10-episode ensemble drama series created by Neil LaBute and airing on DirecTV’s Audience Network channel.
In 2014, Walsh had a supporting role in the first season of FX’s television series Fargo. She had a guest starring role in Hulu’s original series The Hotwives of Orlando and later starred in the NBC series Bad Judge, which aired for one season. As of 2017, Walsh stars in the Netflix drama series 13 Reasons Why, as the mother of a child who commits suicide. Her performance was met with critical acclaim, having been dubbed the “best work” of her career.
In 2019 and 2020, Walsh had a significant recurring role as “the Handler” in the Netflix series The Umbrella Academy. Her most recent role has been on Netflix Original, Emily in Paris, where she plays Emily’s boss who gets pregnant and can no longer move to Paris for their marketing job, so she sends Emily instead.
In 1995, Walsh starred in her first film. Normal Life, a crime drama, was her film debut; she played the sister of a bank robber played by Luke Perry. In Peppermills, she portrayed a kleptomaniac. Walsh appeared in the cult film Henry: Portrait of a Serial Killer, Part II. She gained attention in a major Hollywood production as Will Ferrell’s character’s wife in the family comedy, Kicking & Screaming. Walsh has appeared in several other films with Ferrell, including Bewitched and in Wake Up, Ron Burgundy: The Lost Movie, an “alternate film” to Anchorman.
Walsh founded Boyfriend LLC, a beauty and lifestyle company in 2010. The company launched its first product in November 2010: a perfume called “Boyfriend”. HSN, a leading multichannel retailer, and Walsh partnered to launch the “Boyfriend” fragrance with live appearances by the actress/entrepreneur on HSN, November 11 and 12. Walsh’s fragrance train case, including Boyfriend eau de perfume, pulse point oil and votive candles, sold out on day one exceeding sales expectations.