Nos nem biztos, hogy félig. Édesapja Pedro Olmos, akinek magyar-zsidó eredete van (azt nem tudom, hogy kivándorolt magyar, vagy már kint született). Maga E.J. Olmos is csak az 1970-es években tudta meg, hogy európai gyökerei vannak:
Olmos recounted to the audience how he discovered that he was a descendant of Hungarian Jews. Twenty-one years ago, an older man recognized him in a store and told him that he knew about the origin of his last name. The man told Olmos that his name was Hungarian for “he who works with lead.”
For most of his life, Olmos had thought of himself as purely Mexican American. The news that his name was of European origin stunned him. “A reality hits you and you face it,” Olmos said. He spoke of the joint indigenous and European ancestry Mexicans and Mexican Americans hold because of European conquest of the area.