Donnet is a French surname. Notable people with the surname include:
Ferdinand-François-Auguste Donnet (1795–1882), French cardinal James Donnet (1816–1905), British Royal Navy surgeon Jean-Baptiste Donnet (1923–2014), French chemist Jenny Donnet (born 1963), Australian diver Martial Donnet (born 1956), Swiss alpine skier Matías Donnet (born 1980), Argentine footballer Michel Donnet (1917–2013), Belgian Air Force and Royal Air Force officer