Mía Maestro was born in Buenos Aires, Argentina in 1978. She has accrued a selection of wide ranging film credits since she made her screen debut in Carlos Saura’s Tango, which received Golden Globe and Academy Award nominations for best foreign film. Initially trained in Argentina, Maestro traveled to Berlin to develop a vocal repertoire of the works of Kurt Weill and Hans Eisler. Her first proper acting turn was in the play The Summer Trilogy by Carlo Goldoni, and by 1998, she secured the coveted role of 'Lulu' in Frank Wedekind’s Pandora’s Box at the San Martin Theater in her hometown Buenos Aires. For this she garnered an "Ace" Award for Best New Artist of the Year.
In 2004 she joined the cast of ABC’s critically acclaimed series Alias for two seasons. In the same year, Maestro also appeared in the Argentine film, La Niña Santa (aka The Holy Girl), directed by Lucrecia Martel, as well as the Focus Features film The Motorcycle Diaries, (Golden Globe nominee 2005 Best Foreign Film) based on the journals of Che Guevara, leader of the Cuban Revolution. The film was directed by Walter Salles (Central Station), and stars Gael Garcia Bernal and Rodrigo de la Serna. Maestro has starred as a victim of a kidnapping in Venezuela in Jonathan Jakubowicz’s thriller Secuestro Express, released by Miramax. In December 2005, she starred in Prince's music video for "Te Amo Corazón" which was directed by her friend Salma Hayek.
In 2006 she co-starred in Wolfgang Petersen's film Poseidon, a remake of the 1972 film of the same name. She played Elena Gonzalaz, a stowaway girl going to meet her sick brother in the hospital with friend and waiter Valentine.
Maestro has also starred in the off-Broadway musical play, My Life as a Fairytale, inspired by the life and works of author Hans Christian Andersen and singing the music of Stephin Merritt from the Magnetic Fields. She also starred in Cosí, based on the opera Così fan tutte by Mozart; the comedy Meant to Be; and the American indie film Mr. Tambourine Man based on an Oliver Sacks story.
Maestro has been cast as the lead character in Cutthroat, an ABC television pilot for the 2010-2011 season. As of September 30, 2010, she has been cast as Carmen of the Denali Coven in The Twilight Saga: Breaking Dawn Parts 1 and 2.