Mario Casas Sierra was born in A Coruña, Galicia in 1986 but Casas family moved to Barcelona in 1994, now he lives in Esparraguera. He started with little TV ads, and later he realized that he really wanted to be an actor. He studied in Escuela de Interpretación de Cristina Rota. His first experience on the small screen was ‘La Obsesión’ in 2005. From here he went through several television series that gradually would be released in his name.
His first experience in the world of cinema was in the hands of Antonio Banderas that gave him the opportunity to participate in the film ‘El camino de Los Ingleses’. It was in 2007 when Mario came to the series that would attribute all the fame in this country: Los hombres de Paco. Antena 3 production gave him the opportunity to play a rookie cop named Aitor.
He had a hit in 2010 with Tres Metros Sobre el Cielo. It is a Spanish film directed by Fernando Gonzalez Molina and starring Mario Casas and Maria Valverde. Based on the novel published by the Italian Federico Moccia, he was the protagonist. The second part of 3MSC is Tengo Ganas de Ti which that was a great success too.