Alfonso III

Alfonso III (Spanish) or Afonso III (Portuguese) may refer to:


 * Alfonso III of Asturias (866–910), surnamed "the Great"
 * Afonso III of Portugal (1210–1279)
 * Alfonso III of Aragon (1285–1291)
 * Alfonso III d'Este, Duke of Modena and Reggio (1628–1644)
 * Afonso III of Kongo (1666–1667)