Delassus is a surname. Notable people with the surname include:
Anatole Delassus (born 2001), French slalom canoeist Doriane Delassus (born 2002), French slalom canoeist Henri Delassus (1836–1921), French Roman Catholic priest and anti-Masonic writer Jean-François Delassus (born 1942), French journalist and director Marjorie Delassus (born 1998), French slalom canoeist
See also De Lassus, Missouri, unincorporated area Orlando di Lasso (c. 1532–1594), sometimes cited as "de Lassus"