Amy Louise Acker (born December 5, 1976) is an American actress, best known for her roles as Root on the scifi drama series Person of Interest (2012-2016), Caitlin Strucker on the superhero drama series The Gifted (2017-2019, based on Marvel Comics' X-Men), Winifred Burkle / Illyria on the supernatural drama series Angel (2001-2004), and Kelly Peyton on the action drama series Alias (2005-2006).

She has been married to actor James Carpinello since 2003 and they have 2 children.