He was Ambassador from the United Kingdom to Japan (1980–84), President of the Asiatic Society of Japan (1982–1983) and Chairman of the Japan Society of London (1985–95).
In 1947, Cortazzi joined the Foreign Office.
The British Foreign Office posted Cortazzi to:
- Singapore, 1950–1951
- Tokyo, 1951–1954
- Whitehall, 1954–1958
- Bonn (1958–1960)
- Tokyo, 1961–1965
- London, 1965–1966
- Tokyo, 1966–1970
- Royal College of Defence Studies, 1971–1972
- Washington, D.C., 1972–1975
Cortazzi was made Deputy Under-Secretary of State, in 1975. He became the British Ambassador to Japan in 1980. He spent the next four years in Tokyo.
Sir Hugh has written, edited, translated or contributed to books on the diplomatic history of Japan and the United Kingdom. He also wrote about Japanese history and culture.
- Order of St Michael and St George, Companion (CMG), 1969.
- Order of St Michael and St George, Knight Commander (KCMG), 1980.
- Order of St Michael and St George, Knight Grand Cross (GCMG), 1984.
- University of Stirling, Honorary doctorate, 1988.
- Order of the Sacred Treasure, Grand Cordon (Japan), 1995.
- Cortazzi, Hugh at Visual International Authority File (VIAF)
- Cortazzi, Hugh. "A Japanese sense of humor?", Japan Times. 27 March 2007.
- Books by Hugh Cortazzi
- Japan Society