William Frederick Grant (born October 20, 1924 – October 6, 2011) was a Canadian plant geneticist, biosystematist, educator, and environmental advocate who developed higher plant species for monitoring and testing for mutagenic effects of environmental pollutants.
He has carried out research on the genetics of species of the genus Lotus (Leguminosae) and the forage species Lotus corniculatus (birdsfoot trefoil) developing an innovative procedure for increasing seed production in the legume birdsfoot trefoil.