Serafino Belfanti (Castelletto sul Ticino in Novara province, March 28, 1860 - Milan, March 6, 1939) was an Italian immunologist, founder of the Istituto Sieroterapico Milanese, the first Italian medical and vaccine research institute. After graduating in medical sciences, he worked at the Pasteur Institute in Paris and later with Prof. Koch. In 1932 he was made an Italian senator honoris causa.