Julia Garner (born February 1, 1994) is an American actress and model. She has appeared in the films Martha Marcy May Marlene, The Perks of Being a Wallflower, Sin City: A Dame to Kill For, and has leading roles in Electrick Children, We Are What We Are and Grandma. She has also appeared in the major role of Ruth Langmore in the Netflix original series Ozark and in several episodes of the television series The Americans.