Amanda Michelle Seyfried (pronounced "See-Freed", IPA: /əmænə mɪʃɛl saɪfrɪd/;) born December 3, 1985 is an American actress and former child model. She is best known for her role as Sophie Sheridan in the feature film Mamma Mia!, she has also appeared in Alpha Dog and Mean Girls, and in the television shows Veronica Mars and Big Love.Seyfried started her career as a model at age 11. From there she went on to acting uncredited in the daytime drama Guiding Light. In 2000, she originated the role of Lucy Montgomery on As the World Turns. From 2002 to 2003, she played the role of Joni Stafford on ABC's All My Children.
Seyfried has had minor guest roles on House, M.D., Justice, Law & Order: Special Victims Unit and CSI: Crime Scene Investigation and as Rebecca on Wildfire. Seyfried is also a main character, Sarah Henrickson, in the series Big Love.
She played supporting roles in the 2007 films Alpha Dog and Solstice, and had her first lead role of the bride Sophie in the film version of the musical Mamma Mia!.
Seyfried has joined the cast of the dark horror film Jennifer's Body in February 2008, which filming began in March 2008, playing the title character's best friend. Also in 2008, she played the lead role of Sophie in Mamma Mia! The Movie alongside Meryl Streep and Pierce Brosnan. Her musical performance in that film is also available on Mamma Mia! The Movie Soundtrack.