Jean-Alexandre-Marc Yersin (5 April 1825, in Morges – 2 September 1863, in Lavaux) was a Swiss entomologist.
He died three weeks before the birth of Alexandre Emile Jean Yersin, who became famous for discovering the causative agent of the plague, the bacterium Yersinia pestis.
The renowned son developed his interest in biology at the age of eight, finding and inspecting his father's collection of insects.
His publications include Sur quelques Orthoptères nouveaux ou peu connus du midi de la France Bull.
nat., 8 p., 1 plate (1854) and Note sur quelques Orthoptères nouveaux ou peu connus d'Europes Ann.