The Aden Protectorate (Arabic: محمية عدن Maḥmiyyat ‘Adan) was a British protectorate in South Arabia which evolved in the hinterland of the port of Aden and in the Hadhramaut following the conquest of Aden by the Bombay Presidency of British India in 1839, and it continued until the 1960s. In 1940 it was divided for administrative purposes into the Western Protectorate and the Eastern Protectorate. Today the territory forms part of the Republic of Yemen.

The rulers of the Aden Protectorate, as generally with the other British protectorates and protected states, remained sovereign: their flags still flew over their government buildings, government was still carried out by them or in their names, and their states maintained a distinct 'international personality' in the eyes of international law, in contrast to states forming part of the British Empire, such as Aden Colony, where the British monarch was the head of state.