Younger sister of Mary-Kate and Ashley Olsen who emerged as a talented horror film actress in Martha Marcy May Marlene and Silent House. She played Elle Brody in the 2014 film Godzilla and Scarlet Witch in the 2015 blockbuster Avengers: Age of Ultron .
She took ballet and singing lessons as a child and studied acting at New York University's Tisch School of the Arts and the Atlantic Theater Company.
She played the lead actress in the 2013 film Oldboy , a remake of the cult 2003 South Korean film of the same name.
From 2012 to 2015, she dated actor Boyd Holbrook , whom she met on the set of the film Very Good Girls. She then began dating Tom Hiddleston . In September 2017, her relationship with musician Robbie Arnett became public.