Ali III ibn al-Husayn ( ; 14 August 1817 – 11 June 1902) commonly known as Ali III Bey () was the Husainid Bey of Tunis from 1882 until his death. He was the first ruler under the French protectorate. The old ruler, more popular than his late brother, was overcome with emotion at his inability to act on their petition. 'You have come to weep in the house of tears' he replied to them. The colonial authorities took punitive action against the leaders of the demonstration without his being able to assist them. Cambon responded to this show of protest by sending leading figures into exile in El Kef and Gabes, and dismissing the top city officials from their posts on the grounds that they were 'fanatics hostile to the Protectorate'.
Ali Bey withdrew increasingly from the affairs of state before he died. He was buried in the Tourbet el Bey mausoleum in the medina of Tunis and succeeded by his son Muhammad IV al-Hadi.