Sir William Ivo Mallet GBE KCMG (7 April 1900 – 7 December 1988) was a British diplomat who served as ambassador to Yugoslavia and Spain.
Mallet was educated at Harrow School and Balliol College, Oxford.
[6] Meanwhile, Mallet served as ambassador to Yugoslavia 1951–54,[7] where he was involved in lengthy negotiations on the fate of Trieste which at one point brought Italy and Yugoslavia close to war,[8] and as ambassador to Spain 1954–60,[9] also a difficult time under General Franco.
In 1929, in Warsaw, Ivo Mallet married Marie-Angèle Wierusz-Kowalska (daughter of the Polish ambassador to the Vatican Józef Wierusz-Kowalski and his wife Leonia, countess Rostworowska[11]).
They had two sons and a daughter, Joan, who in 1955 married the British diplomat Robert Farquharson (who was also to be ambassador to Yugoslavia 1977–80).