American actress, comedian, and musician. She stars as Marnie Michaels on the HBO television series, Girls. Williams is the daughter of Jane Gillan Stoddard and NBC Nightly News anchor Brian Williams. Williams was raised in New Canaan, Connecticut. She attended Yale University and graduated in 2010 with an English degree. While at Yale, Williams was a member of the improv comedy troupe Just Add Water for four years, as well as being a part of the YouTube web series College Musical, and was inducted into St. Elmo.
In 2010, Williams performed a mashup of “Nature Boy” set to RJD2′s “A Beautiful Mine”, the theme song for the television series Mad Men. The YouTube video of the performance received widespread praise on the Internet,and convinced Judd Apatow that she should be given a part in the HBO TV series Girls. She was cast shortly after and credited her experience at Just Add Water for passing the auditionGirls premiered on April 15, 2012.
Williams wrote a series of Funny or Die sketches in which she starred as newlywed Kate Middleton with British actor and model Oliver Jackson-Cohen as Prince William, Duke of Cambridge. Williams appeared in the third season of The League as Danielle in the episode “The Guest Bong.”