Elizabeth Dean Lail (born March 25, 1992) is an American actress. She is known for her starring roles as Amy Hughes in the 2016 Freeform television series Dead of Summer and as Guinevere Beck in the 2018 Lifetime television series You, and for her recurring role as Anna in the fourth season of the ABC adventure fantasy television series Once Upon a Time.
Lail was born in Williamson County, Texas, to her parents, Dean Franklin Lail and wife Kay Lurene Surratt. She has one older sister. Lail grew up in Asheboro, North Carolina. After graduating from Asheboro High School in 2009, she attended the University of North Carolina School of the Arts, graduating in May 2014.
Lail mostly worked in student film productions, such as Model Airplane and Without, immediately after graduating from university. She had moved to New York City to pursue stage work when she landed an audition for ABC's Once Upon a Time, after which she was cast as Anna in the fourth season of the series. Lail was cast in a starring role in the Freeform horror series Dead of Summer playing the role of camp counselor Amy. On July 27, 2017, Lail was cast as a female lead in the Lifetime television series, You, opposite Penn Badgley and Shay Mitchell.