Fran Jesenko (14 March 1875 – 14 July 1932) was a Slovenian botanist and plant geneticist who became notable for his work on the hybridisation of wheat and rye.

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.

[2][3] In 1909, he became a research assistant under Erich von Tschermak at the College of Agriculture (Hochschule für Bodenkultur; now University of Natural Resources and Life Sciences) in Vienna, and a lecturer in 1913.

He used to spend summers there, studying alpine flora with students and contributing to the area's permanent legal protection, which was only secured in 1981, long after Jesenko's death.

[1][4] The award given by the Biotechnical faculty since 1972 is named in his honor (Slovene: Jesenkovo priznanje), as are a street in Ljubljana[4] and the 3-kilometre (1.9 mi) Jesenko Trail on Rožnik hill.