Hugh Iltis (April 7, 1925 – December 19, 2016) was a professor of botany and director of the herbarium at the University of Wisconsin–Madison. While he is most noted as a scientist for his role in the discovery of perennial teosinte (Zea diploperennis), a wild diploid relative of modern maize (Zea mays), he is also remembered as an outspoken environmental conservationist.