Seyfried began her career as a child model when she was 11 and at 15 began her career as an actress, starting off with uncredited roles and moving on to recurring roles on As the World Turns and All My Children.
Amanda Seyfried mother, Ann (née Sander), is an occupational therapist, and her father, Jack Seyfried, is a pharmacist.
Amanda Michelle Seyfried is of mostly German descent, and also has some Scots-Irish and English ancestry.
Seyfried graduated in 2003 from Allentown's William Allen High School.
Amanda Seyfried has an older sister, Jennifer Seyfried, who is a musician in the Philadelphia organ-driven rock band, Love City.