The Sultanate of Zanzibar (Swahili: Usultani wa Zanzibar, Arabic: سلطنة زنجبار, translit. Sulṭanat Zanjībār), also known as the Zanzibar Sultanate, comprised the territories over which the Sultan of Zanzibar was the sovereign. Those territories varied over time, and at one point included all of what is now Kenya as well as the Zanzibar Archipelago of the Swahili Coast. Later, the kingdom's realm included only a ten mile wide coastal strip of Kenya and Zanzibar. Under an agreement concluded on 8 October 1963, the Sultan relinquished sovereignty over his remaining territory in Kenya. On 12 January 1964, Sultan Jamshid bin Abdullah was deposed and lost sovereignty over the last of his dominions, Zanzibar.
Zanzibar is now a semi-autonomous region of Tanzania.