Amanda Seyfried began her career as a model, for eleven years. In 2000 she debuted as an actress in the world of soap operas, participating in As the World Turns and after All My Children. In 2004 she made her debut in cinema with the teen comedy Mean Girls, where she played the ditzy Karen. From 2004 to 2006 plays Lilly Kane in the television series Veronica Mars and also appears in other television series like Law & Order, Dr. House, CSI, Wildfire. In 2005 she obtained a role in the film 9 Women lives.
In 2006 gets the part of Julie Beckley in Alpha Dog by Nick Cassavetes. In the same year she joined the cast of the HBO series Big Love. In 2008 she works in her first horror Solstice, playing the best friend of the protagonist. She achieves success in Mamma Mia!, the film adaptation of the homonymous musical, where she demonstrates her singing talent alongside Meryl Streep. In February 2008, she has a role to co-star in the black / horror comedy Jennifer’s Body opposite to Megan Fox. In 2009 she was announced that will be part of the cast of Albert Nobbs, but finally the part is given to Mia Wasikowska. In the same year she co-starred in the erotic drama Chloe and deceit in the role of a prostitute opposite Julianne Moore and Liam Neeson. Later plays Paige in Boogie Woogie.
In 2010 we saw her in Letters to Juliet, a movie with a cast that includes Vanessa Redgrave, Gael García Bernal, Franco Nero and Christopher Egan. In 2010 she starred as a co-star opposite Channing Tatum in the movie Dear John, based on the book by Nicholas Sparks, Dear John Moon. In 2011 she is taken into account by Zack Snyder for the lead role in Sucker Punch, but she has to give up because of other commitments. Finally for the part was chosen Emily Browning. A short time later she starred in Catherine Hardwicke’s Red Riding Hood film, where Seyfried has the starring role, opposite Gary Oldman. Also in 2011 she co-starred in the movie In Time. A year after released the film Gone by Heitor Dhalia, where Amanda is the protagonist. In 2012 as an adult plays Cosette in the film Les Misérables by Tom Hooper, alongside Hugh Jackman and Russell Crowe.
Seyfried in the film proves to possess a voice of soprano. In the same year she joined the cast of Big Wedding, starring Robert De Niro, Diane Keaton, Susan Sarandon, Katherine Heigl, Robin Williams and many others. In 2013 double star in the animated film Epic, before being cast as the lead of the controversial film Lovelace, the biopic of porn star Linda Lovelace. In 2014 plays Louise in the comedy westerns A million ways to die in the West directed by Seth MacFarlane, with Charlize Theron, Liam Neeson and the same Seth MacFarlane. In 2015 she is in While We’re Young, the dramatic comedy starring Ben Stiller and Naomi Watts, directed by Noah Baumbach. She is also in Pan, which narrates the first time that Peter Pan arrives on the island that is not there, where Amanda plays Mary, mother of Peter. Following is the female protagonist of Fathers and Daughters by Gabriele Muccino, in which she plays the daughter of Russell Crowe. The September 18, 2015 joined the cast of the revival of Twin Peaks.