Elizabeth Joanna Mitchell (née Robertson; born March 27, 1970), is an American actress who is known for her roles as Dr. Juliet Burke on ABC's TV series Lost and as FBI agent Erica Evans on V. She has starred such films as The Santa Clause 2, The Santa Clause 3: The Escape Clause and Gia. Mitchell currently co-stars in Eric Kripke's television series Revolution, airing on NBC.

Her stepfather, Joseph Day Mitchell, and mother, Josephine Marian Mitchell (née Jenkins), are lawyers based in Dallas. Mitchell and her mother moved to Dallas, Texas in 1970, where her mother married Joseph Mitchell in 1975. Mitchell graduated from Booker T. Washington High School for the Performing and Visual Arts, a public magnet school. She is the eldest of three sisters, the others being Kristina Helen "Kristie" Mitchell (b. 1977), and Katherine Day "Kate" Mitchell (b. 1981). In 1991, she graduated from Stephens College with a Bachelor of Fine Arts in acting, and also studying at the British American Drama Academy.Mitchell worked for six years in Dallas Theater Center and a year at Encore Theater.