Katherine Victoria Litwack (born June 13, 1986), known professionally as Kat Dennings, is an American actress. She is known for her starring roles as Max Black in the CBS sitcom 2 Broke Girls (2011–2017) and as Darcy Lewis in the Marvel Cinematic Universe superhero films Thor (2011), Thor: The Dark World (2013), Thor: Love and Thunder (2022), and the Disney miniseries WandaVision (2021).

Since making her acting debut in 2000, Dennings has appeared in films including The 40-Year-Old Virgin (2005), Big Momma's House 2 (2006), Charlie Bartlett (2007), The House Bunny (2008), Nick and Norah's Infinite Playlist (2008), Defendor (2009), and Suburban Gothic (2014).

Early life
Katherine Victoria Litwack was born on June 13, 1986, in Bryn Mawr, Pennsylvania. Her mother, Ellen Judith Litwack, is a poet and speech therapist, and her father, Gerald J. Litwack, is a molecular pharmacologist, and college professor and chairman. Dennings is the youngest of five children. Her family is Jewish. Dennings grew up in Penn Cottage, a historic house built in 1694 in Wynnewood, Pennsylvania, which she claims was haunted.

Beginning her career at age 9 by acting in commercials, Dennings said her family never had much money for formal acting training. Her first acting job was an advertisement for potato chips that included a poisonous ingredient and never made it to market. In her early years, she worked as an extra to earn her SAG card.

Dennings was homeschooled; her only enrollment at a traditional school was for a half-day at Friends' Central School. She graduated from high school early at age 14, and moved with her family to Los Angeles to pursue acting full time. In an interview with Philadelphia magazine in 2008, she explained that she chose "Dennings" as her professional surname because she thought her family name was "a little hideous" and she "wanted to know when someone really knew  or they didn't."