Fran Jesenko (March 14, 1875 – July 14, 1932) was a Slovenian botanist and plant geneticist who became notable for his work on the hybridisation of wheat and rye.After attending high school in Ljubljana, Jesenko enrolled in the University of Vienna and graduated in 1902. During his studies, he became a tutor to two Oriental princes at Vienna's Teresianum college for boys, later also serving in this capacity for Count Merveldt.