Humphrey of Hauteville (c. 1010 – August 1057), surnamed Abagelard, was the Count of Apulia and Calabria from 1051 to his death.
Humphrey was probably the youngest son of Tancred of Hauteville by his first wife Muriel. Some sources make Geoffrey and Serlo his younger brothers. He is usually said to have accompanied his elder brothers William and Drogo to the Mezzogiorno circa 1035 on the basis of Goffredo Malaterra; however, he may have arrived later, in 1044, during the reign of his elder brother William. Around 1047, he was granted the lordship (or countship) of Lavello by his brother Drogo, whom he succeeded as Count of Apulia in August 1051. In his early years in Lavello, he employed a young Richard Drengot, who was later to serve him against the pope. In 1053, Humphrey received his three brothers, Geoffrey and their half-brothers Mauger and a younger William, on their arrival in Italy. He granted Mauger the Capitanate and William the Principate.
His reign began amid the troubles which had ended his brother's. Humphrey vigorously punished the instigators of his brother's assassination, especially the principal murderer. Many Norman knights were in rebellion and pillaging papal lands. Guaimar IV of Salerno supported Humphrey's succession, but he was soon assassinated. Pope Leo IX organised a coalition against the Normans and marched south. The pope's forces and those of the Normans fought the Battle of Civitate near Civitate sul Fortore on 18 June 1053. Humphrey led the armies of the Hautevilles (assisted by his younger half-brother Robert Guiscard) and Drengots (assisted by Richard Drengot) against the combined forces of the Papacy and the Holy Roman Empire. The Normans destroyed the papal army and captured the pope, whom they imprisoned in Benevento, which they had been authorised by the emperor to capture in 1047. They finally released him on 12 March 1054. Leo died soon after.