Johan Rutger Sernander (November 2, 1866 - October 27, 1944) was a Swedish botanist, geologist and archaeologist. He was one of the founders of the study of palynology which would later be developed by Lennart von Post, as well as a pioneer in the early Swedish natural conservation and ecology movements.He was among other societies a member of the Royal Swedish Academy of Sciences, the Royal Swedish Academy of Letters, History and Antiquities and Norwegian Academy of Science and Letters.