Erica McDermott is an American actress. In 2010, she made her cinematic debut in the film Knight and Day. That same year, she played Cindy “Tar” Eklund in the acclaimed movie The Fighter. Her role here got her a MTV nomination. The following year, she had her first television role in Body of Proof. Afterward, she had roles in the films The Rude, the Mad, and the Funny and Last Hours in Suburbia. McDermott went on to appear in the movies American Hustle, Black Mass, and Joy. Her most recent works in the movies were in Manchester by the Sea and Patriots Day.