Giuseppe De Notaris (18 April 1805, Milan – 22 January 1877) was an Italian botanist generally known for his work with cryptogams native to Italy. He studied medicine at the University of Pavia, obtaining his medical degree in 1830. Having developed an interest in botany, by 1832 he had abandoned the field of medicine. In 1836 he accepted an assignment at the botanical garden in Turin, and a few years later, was named professor of botany and director of the botanical garden at the University of Genoa (1839). In 1872 he was appointed chair of botany at the University of Rome.