Alan Watt, Australian public servant and diplomat, Australian Ambassador to Japan (d. 1988)
Sir Alan Stewart Watt (13 April 1901 – 18 September 1988) was a distinguished Australian diplomat.

Born of Scottish heritage, Watt attended Sydney Boys High School. A graduate of the Universities of Sydney and Oxford, he was a New South Wales Rhodes Scholar for 1921. In 1924, he played singles and doubles tennis at Wimbledon as the captain of Oxford.Watt first joined the Commonwealth Public Service in the Department of External Affairs, in 1937. He served in the United States during World War II and was one of the Australian delegates at the United Nations Conference on International Organization. In 1947 Watt became the Australian minister to the Soviet Union and in 1948 the first Australian Ambassador in Moscow. In 1950 he returned to Australia and was appointed Secretary to the Department and was instrumental in negotiation of the ANZUS and SEATO treaties. He then served as High Commissioner to both Singapore and Southeast Asia (1954–1956), Ambassador to Japan (1956–1960) and Ambassador to Germany (1960–1962). Leaving the Department of Foreign Affairs in 1962, he became a Visiting Fellow of the Australian National University, and Director of the Australian Institute of International Affairs (1963–1969).He wrote a number of books and articles in retirement, including The Evolution of Australian Foreign Policy 1938–1965 (1967, Cambridge University Press, 67-10782), Vietnam - An Australian Analysis (1968, Melbourne, F. W. Cheshire for Australian Institute of International Relations), and Australian Diplomat - Memoirs of Sir Alan Watt (1972, Angus and Robertson, ISBN 0-207-12354-3).