He was born in Puerto Vallarta, Jalisco, Mexico to an Irish-American mother and a Mexican father. Diaz speaks English and Spanish fluently and lived for several years in Palo Alto, California. He finished high school in Palo Alto, before returning to Mexico to study at the exclusive Televisa Acting School Centro de Educación Artística (CEA). He made his acting debut in the popular teen drama Clase 406, playing the role of Kike González. In 2004, he followed Clase 406 with another teen drama titled Corazones al límite co-starring Sherlyn and Sara Maldonado. He then played the role of the older Andrés Romero in the telenovela Barrera de amor starring Yadhira Carrillo. He starred along former flame Sherlyn in Mexico's own version of Grease entitled Vaselina.