New Yorker Claire Catherine Danes was born in Manhattan, the daughter of Carla (Hall), a day-care provider and artist, and Christopher Danes, a computer consultant and photographer. She has an older brother, Asa. Her paternal grandfather, Gibson Andrew Danes, was a Dean of the Yale School of Art and Architecture. She is of mostly German and British Isles descent.

Claire was educated at Dalton School, New York, The New York City Lab School for Collaborative Studies, The Professional Performing Arts School and Lycée Français de Los Angeles. From 1998, she attended Yale University, studying psychology, but dropped out after two years to concentrate on her acting career.

Danes first came to major public attention when she appeared as "Angela Chase" in My So-Called Life (1994). She won an Emmy nomination and a Golden Globe award for this performance. A successful film career followed, including the role of "Juliet", opposite Leonardo DiCaprio, in Baz Luhrmann's Romeo + Juliet (1996). She continued acting in such varied project as The Hours (2002), Terminator 3: Rise of the Machines (2003) and Stardust (2007).

In 2010, she appeared in the HBO Production, Temple Grandin (2010), playing the title character. She received huge critical acclaim for the role, and won an Emmy, Golden Globe and Screen Actors Guild Award for her performance. Since 2011, she has starred on the SHOWTIME series Homeland (2011), receiving great critical acclaim and winning Emmys and Golden Globes.