Newsom was not allowed to watch television or listen to the radio when she was a child. She went to a Waldorf school. After high school Newsom studied composition and creative writing at Mills College in Oakland, California.
Newsom's first album The Milk-Eyed Mender was released by Drag City on the 23rd of February 2003. Pitchfork gave the album a score of 8 out of 10. Newsom's second album Ys was given a score of 9.4 out of 10.
She married comedian Andy Samberg in September 2013.
- The Milk-Eyed Mender (Drag City, 2004)
- Ys (Drag City, 2006) US #134, UK #41
- Have One on Me (Drag City, 2010) US #75, UK #28
- Divers (Drag City, 2015)
- Early unofficial recordings
- Walnut Whales (self-released, 2002)
- Yarn and Glue (self-released, 2003)
- "Sprout and the Bean" (Drag City, 2004)
- "What We Have Known" (Drag City, 2011)