Lauren Ambrose (born Lauren Anne D'Ambruoso, February 20, 1978) is an American actress and singer. She is known for her television roles as Claire Fisher in Six Feet Under (2001–2005), for which she won two Screen Actors Guild Awards; and as Jilly Kitzinger in Torchwood: Miracle Day (2011). Her film credits include Can't Hardly Wait (1998), Psycho Beach Party (2000) and Where the Wild Things Are (2009).
She is the lead singer of the ragtime band Lauren Ambrose and the Leisure Class.
Ambrose was born in New Haven, Connecticut. She is the daughter of Frank D'Ambruoso, a caterer and Anne (née Wachtel), an interior designer. She is of Italian descent on her father's side and German, English, and Irish on her mother's. Ambrose attended Choate Rosemary Hall in Wallingford, Connecticut, Wilbur Cross High School, High School in the Community, and the ACES Educational Center for the Arts in New Haven. She is also a trained opera singer who studied voice and opera at the Boston University Tanglewood Institute.