Alfonso of Hauteville (Latin: Anfusus) (c. 1120 – 10 October 1144), third son of Roger II of Sicily and Elvira of Castile, was the prince of Capua from 1135 to his death.
He was named after his maternal grandfather, Alfonso VI of Castile. His maternal grandmother was Alfonso VI's fourth wife Isabel, possibly the same person as Zaida, converted daughter-in-law of al-Mutamid of Seville.
Though his birth date is unknown, he was old enough to wage war to maintain his principality when, in 1135, his father gave him the principality of Capua, thus dethroning the rebellious reigning prince, Robert II, of the House of Drengot. He appointed his chancellor Guarin to act as the young Alfonso's administrator. This action effectually brought Capua into the sphere of Hauteville power, though Roger attended Alfonso's enthronement as suzerain, not ruler. On 25 July 1139, by the Treaty of Mignano, he received the papal recognition of Innocent II, taking up the same position vis-a-vis the papacy which the old Drengot princes long held.
On the death of Sergius VII of Naples, who had thrown open his city's gates to Roger II, Alfonso was elected duke of Naples. In April 1140, with his elder brother Roger III, whom their father had made duke of Apulia, he invaded the Abruzzo, conquering much land including the important coastal city of Pescara. He stretched his dominion as far as the Tronto river. He died on 10 October 1144 during a second invasion with his brother, this time in Latium against Pope Lucius II, where they marched on Rieti and Cagnano Amiterno.