# List of ambassadors of the United States to Tanzania

The present country of Tanzania, officially the United Republic of Tanzania, was created upon the union of the formerly independent countries of Tanganyika and the People's Republic of Zanzibar (P.R.Z.).
Tanganyika became independent from the United Kingdom (U.K.) on December 9, 1961. The United States (U.S.) immediately recognized the new nation and moved to establish diplomatic relations. The U.S. embassy in Dar es Salaam opened on the day of Tanganyika's independence. William R. Duggan served as the chargé d'affaires ad interim pending the appointment of an ambassador.
The Sultanate of Zanzibar became independent from the U.K. on December 19, 1963, as a constitutional monarchy headed by its sultan. The U.S. established an embassy in Zanzibar on December 10, 1963, with Frederick P. Picard III serving as chargé d'affaires ad interim. In January 1964, the sultan was overthrown and the P.R.Z. was established.
On April 26, 1964, Tanganyika united with the P.R.Z. to form the United Republic of Tanganyika and Zanzibar (U.R.T.Z.). The U.S. ambassador to Tanganyika, William K. Leonhart, immediately became the ambassador to the U.R.T.Z. A U.S. ambassador to the P.R.Z. had not yet been appointed when that country united with Tanganyika. In lieu of an ambassador, Frank C. Carlucci III was serving as the chargé d'affaires ad interim and continued in that capacity until the U.S. embassy was downgraded to a consulate general on June 27, 1964.
The country was renamed the United Republic of Tanzania on October 29, 1964.
The U.S. did not have an ambassador to Tanzania from October 2016 to August 2020.

## Ambassadors

| Name | Title | Appointed | Presented credentials | Terminated mission | Notes |
| William K. Leonhart – Career FSO | Ambassador Extraordinary and Plenipotentiary | August 22, 1962 | October 3, 1962 | December 22, 1965 | Leonhart was originally commissioned to Tanganyika. He was recommissioned when Tanganyika became a republic and presented new credentials on December 17, 1962. Leonhart continued to serve without further reaccreditation after the formation of the United Republic of Tanganyika and Zanzibar |
| John H. Burns – Career FSO | Ambassador Extraordinary and Plenipotentiary | September 24, 1965 | January 3, 1966 | June 22, 1969 | |
| Claude G. Ross – Career FSO | Ambassador Extraordinary and Plenipotentiary | October 9, 1969 | December 27, 1969 | June 25, 1972 | |
| W. Beverly Carter, Jr. – Career FSO | Ambassador Extraordinary and Plenipotentiary | June 27, 1972 | July 24, 1972 | October 14, 1975 | |
| James W. Spain – Career FSO | Ambassador Extraordinary and Plenipotentiary | November 20, 1975 | January 8, 1976 | August 21, 1979 | |
| Richard Noyes Viets – Career FSO | Ambassador Extraordinary and Plenipotentiary | September 28, 1979 | October 18, 1979 | May 16, 1981 | |
| David Charles Miller, Jr. – Political appointee | Ambassador Extraordinary and Plenipotentiary | October 26, 1981 | November 4, 1981 | February 28, 1984 | |
| John William Shirley – Career FSO | Ambassador Extraordinary and Plenipotentiary | June 28, 1984 | July 28, 1984 | July 18, 1986 | |
| Donald K. Petterson – Career FSO | Ambassador Extraordinary and Plenipotentiary | October 16, 1986 | December 8, 1986 | December 26, 1989 | |
| Edmund DeJarnette, Jr. – Career FSO | Ambassador Extraordinary and Plenipotentiary | November 21, 1989 | February 26, 1990 | September 12, 1992 | |
| Peter Jon de Vos – Career FSO | Ambassador Extraordinary and Plenipotentiary | June 15, 1992 | January 8, 1993 | June 3, 1994 | |
| J. Brady Anderson – Political appointee | Ambassador Extraordinary and Plenipotentiary | August 26, 1994 | September 13, 1994 | October 7, 1997 | |
| Charles Richard Stith – Political appointee | Ambassador Extraordinary and Plenipotentiary | June 29, 1998 | September 17, 1998 | January 20, 2001 | |
| Robert V. Royall – Political appointee | Ambassador Extraordinary and Plenipotentiary | November 5, 2001 | December 19, 2001 | November 21, 2003 | The post was vacant from November 2003 until August 2005. Michael S. Owen served as chargé d'affaires ad interim during that time. |
| Michael Retzer – Political appointee | Ambassador Extraordinary and Plenipotentiary | August 24, 2005 | March 9, 2005 | August 31, 2007 | |
| Mark Andrew Green – Political appointee | Ambassador Extraordinary and Plenipotentiary | August 23, 2007 | September 13, 2007 | January 20, 2009 | |
| Alfonso E. Lenhardt – Political appointee | Ambassador Extraordinary and Plenipotentiary | November 12, 2009 | November 12, 2009 | October 9, 2013 | |
| Mark B. Childress – Political appointee | Ambassador Extraordinary and Plenipotentiary | April 7, 2014 | May 22, 2014 | October 25, 2016 | |
| Donald J. Wright – Political appointee | Ambassador Extraordinary and Plenipotentiary | February 14, 2020 | August 2, 2020 | January 11, 2023 | |
| Michael Battle - Political appointee | Ambassador Extraordinary and Plenipotentiary | December 13, 2022 | February 27, 2023 | January 15, 2025 | |
| Andrew Lentz - Career FSO | Chargé d'affaires ad interim | January 15, 2025 | | Incumbent | |