The High Commissioner of the United Kingdom to Tanzania is the United Kingdom's foremost diplomatic representative to the United Republic of Tanzania, and head of the UK's diplomatic mission in Tanzania.
As the United Kingdom and Tanzania are both members of the Commonwealth of Nations, they exchange High Commissioners rather than Ambassadors.
Tanzania was formed in 1964 by the union of the Republic of Tanganyika, formerly a British colony, which had gained independence in 1961, and the People's Republic of Zanzibar and Pemba, which had gained independence in December 1963. The People´s Republic of Zanzibar had been created the previous year during a revolution in the Sultanate of Zanzibar, which 1890–1963 was a semi-independent Protectorate of the United Kingdom.
The High Commissioner to Tanzania is also the UK Representative to the East African Community.