Zorro's Fighting Legion is a 1939 Republic Pictures film serial consisting of twelve chapters. It features Reed Hadley as Zorro. The plot revolves around his alter-ego Don Diego's fight against the evil Don Del Oro.

A trademark of this serial is the sudden demise of at least one native informant in each episode. The direction was identical for each informant's death, creating a source of unintentional humor: each informant, upon uttering the phrase, "Don del Oro is...", is shot by a golden arrow and dies before being able to name the villain's alter ego. The serial is also unusual in featuring a real historical personage, Mexican President Benito Juárez, as a minor character.