Walsh graduates from Tucson's Catalina Magnet High School and studies acting at the University of Arizona and Chicago's renowned Piven Theatre Workshop. The following year, she moves to New York City and joins the comedy troupe Burn Manhattan. "In New York, I'd be, like, 'This is it, man, I've got it now,'" she tells the Lost Angeles Times in 2007. "And then I would collect unemployment. And waitress."
Walsh makes her first memorable TV appearance on the third season of The Drew Carey Show. She dons a fat suit to play Carey's girlfriend Nicki Fifer. "They basically flew me out from New York [to L.A.] for about a five-minute meeting with Drew Carey," she tells the Arizona Republic in 1999. "I took the chance and packed my bag for 30 days and ended up doing 11 episodes."
Walsh makes a supporting appearance in Brett Ratner's feature The Family Man with Nicolas Cage. She also appears in HBO's The Mind of the Married Man, and with Will Ferrell in the 2005 family comedy Kicking & Screaming.
Walsh interrupts the romance between Patrick Dempsey and Ellen Pompeo in the first-season cliffhanger on Grey's Anatomy. She plays the romantically tormented Dr. Addison Montgomery Shepherd on the hit ABC medical drama. "I've been very fortunate to be a working actress who hovered along," Walsh, whose initial appearance on Grey's was only intended for five episodes, tells the Los Angeles Times. "And then it was like, boom, Grey's."
Grey's cast mate Isaiah Washington calls costar T.R. Knight a "faggot." The cast endures a season of bad publicity and on-set tension. Despite the woes, they win a Screen Actors Guild Awards for Outstanding Performance by an Ensemble in a Drama Series. In June 2007, Washington learns his contract is not renewed. Upon hearing the news, Walsh sends him a text message.
Grey's creator Shonda Rhimes develops a spinoff focusing on Walsh's character. Actors Amy Brenneman, Tim Daly and Taye Diggs join the cast, and ABC adds Private Practice to its fall lineup. Meanwhile, Walsh steps out with Alex Young, a 20th Century Fox executive. "You get everything settled in your professional life," Walsh tells PEOPLE, "then you're ready to rock out the love life."
After being named No. 52 on Maxim's Hot 100, Walsh, 39, announces her engagement to Young, who gave her a Neil Lane diamond ring. "He's the most amazing man I've ever met," Walsh tells PEOPLE. In August, she grabs a group of gal pals, including former Grey's Anatomy castmate Sara Ramirez, and heads to Las Vegas for her bachelorette party.
Walsh wears a custom-made Monique Lhuillier wedding gown as she and Young exchange vows in the town of Ojai north of L.A. Among the nearly 100 guests were Grey's stars Katherine Heigl, Chandra Wilson, Sara Ramirez and Justin Chambers, as well as actress Kate Beckinsale. After nearly 15 months of marriage, Young files for divorce in November 2008, citing "irreconcilable differences."
Walsh headlines Entertainment Weekly's Fall TV Preview issue, which calls Private Practice, "the most anticipated show of the year." "I definitely like writing down goals, where I want to be, how I imagine it. But...I didn't write down I'd like my own spin-off," she tells EW of her show which will premiere on Sept. 26. "I was excited...But my first thought was 'Oh, God, what if it doesn't work?'"
A year after her divorce, Walsh hits the Emmy Awards with her new beau, Neil Andrea – but refuses to comment on her personal life. "I'm not going to talk about that! I know you have to ask, but it's super top-secret! It's in the vault!" she tells PEOPLE. In 2011, the pair calls it quits.
BIOGRAPHY (top to bottom): Courtesy of Catalina Magnet High School; ABC; FRANCIS SPECKER/Landov; ABC; NEILL J. SCHUTZER/RAMEY; Jeff Kravitz/FilmMagic; Ben Foster/Broadimage