Don Juan Carlos María Isidro de Borbón, Count of Montizón (French: Jean Charles Marie Isidore de Bourbon, comte de Montizón) (15 May 1822 – 18 November 1887) was the Carlist claimant to the throne of Spain from 1860 to 1868, and the Legitimist claimant to the throne of France from 1883 to 1887, and a possible pretender to Mexican throne before the establishment of the Second Mexican Empire in the 1860s.