Tanganyika, from 1962 to 1964 the Republic of Tanganyika, is a sovereign state in East Africa.

It is situated between the Indian Ocean and the African Great Lakes of Lake Victoria, Lake Nyasa and Lake Tanganyika.

It gains independence from the United Kingdom as a Commonwealth Realm on 9 December 1961, becoming a republic within the Commonwealth of Nations exactly a year later, on 9 December 1962.

On 26 April 1964, Tanganyika joins with the islands of Zanzibar to form the United Republic of Tanganyika and Zanzibar, a new state that changes its name to the United Republic of Tanzania within a year.Tanganyika originally consists of the British share of the former German colony of German East Africa which the British took under a League of Nations Mandate in 1922, which is later transformed into a United Nations Trust Territory after World War II.

The other parts of German East Africa are taken into Belgian Trusteeship, eventually becoming known as modern-day Rwanda and Burundi.