Rising to fame as Marnie Michaels, the best friend of Lena Dunham's Hannah Horvath on HBO's Girls, Allison Williams graduated from Yale before breaking into the entertainment business. The daughter of NBC Nightly News anchor Brian Williams, Allison took part in Yale's improv comedy troupe Just Add Water and became a viral video sensation when she performed a mash-up of Nat King Cole's "Nature Boy" and RJD2's "A Beautiful Mine," and posted the clip to YouTube in 2010. From there, Williams family friend Judd Apatow cast her on HBO's Girls.
Elsewhere, Williams -- who once worked as Tina Fey's assistant -- has appeared as royal Kate Middleton in a Funny or Die web video spoof series, and on The Mindy Project as Jillian.
She is currently dating College Humor co-founder Ricky Van Veen.