Dey, from the Turkish honorific title dayı, literally meaning uncle, was the title given to the rulers of the Regency of Algiers (Algeria), Tripoli, and Tunis under the Ottoman Empire from 1671 onwards. Twenty-nine deys held office from the establishment of the deylicate in Algeria until the French conquest in 1830.

Ottoman Tunisia, also known as the Regency of Tunis, refers to the Ottoman presence in Ifriqiya from the 16th to 19th centuries, when Tunis was officially integrated into the Ottoman Empire as the Eyalet of Tunis. The Ottoman presence in the Maghreb began with the takeover of Algiers in 1516 by the Ottoman Turkish corsair and beylerbey Aruj, eventually expanding across the entire region except for Morocco. The first Ottoman conquest of Tunis occurred in 1534 under the command of Khayr al-Din Barbarossa, the younger brother of Aruj, who was the Kapudan Pasha of the Ottoman Fleet during the reign of Suleiman the Magnificent. However, it was not until the final Ottoman reconquest of Tunis from Spain in 1574 that the Turks permanently acquired the former territories of Hafsid Tunisia, retaining it until the French occupation of Tunisia in 1881.