Dionigi Galletto (26 January 1932 – 25 September 2011) was an Italian mathematician and academician.
He is known for his work on rigid body mechanics, on the mathematical theory of elasticity (including both linear elasticity and finite strain theory), on the history of mathematics and on cosmology and extragalactic celestial mechanics: in particular he is considered one of the founders of the latter branch of cosmology.He was professor of mathematical physics at the University of Turin: as such, he is considered to be the founder–reorganiser of the Mathematical physics school of Turin in the Post–Second World War period.