Cazzaniga is an Italian surname from Milan and Monza and Brianza, derived from the town of Gazzaniga or other toponyms in northwestern Lombardy. Notable people with the surname include:Alicia Cazzaniga (1928–1968), Argentine modernist architect Ignazio Cazzaniga (1911–1974), Italian classical philologist and academic Leonardo Cazzaniga, Italian serial killer and former anesthesiologist Mario Cazzaniga (1900–?), Italian water polo player Tommaso Cazzaniga, Italian football player