Kate Walsh is an American actress and businesswoman, best known for her role as Dr. Addison Montgomery on the television series Grey's Anatomy and its spin-off, Private Practice. Born on October 13, 1967, in San Jose, California, she began her career in theater before transitioning to television and film. In addition to her acting career, Walsh has appeared in various films and TV shows, including The Perks of Being a Wallflower and Fargo. She is also the founder of a skincare line called Boyfriend, which reflects her interest in health and wellness.