Giovanni Enrico Eugenio Vacca (18 November 1872 – 6 January 1953) was an Italian mathematician, Sinologist and historian of science.

In 1899 he studied, at Hanover, unpublished manuscripts of Gottfried Wilhelm Leibniz, which he published in 1903.

He pursued the latter professionally, first, as a lecturer of Chinese language and literature at the Istituto di studi superiori di Firenze in 1910, then, in charge of teaching language and literature of the Far East at the University of Rome from 1911 until 1921, transferred to Florence in succession of Carlo Puini as ordinario for History and Geography of East Asia, and finally at the University of Rome, where he held the chair for History and Geography of East Asia from 1923 to his retirement in 1948 when he was in his 76th year.

Besides actively contributing to the field of East Asian Studies, Vacca continued in parallel to work on mathematical questions inspired by his intellectual proximity to Peano’s School and his extensive readings of historical sources by Euclid, Archimedes, Euler, Fermat, Napier, and others.

[1] The interests of Vacca were almost equally split between mathematics, Sinology and history of science, with a corresponding number of papers being 38, 47 and 45.