Jakob Friedrich Ehrhart (4 November 1742, Holderbank, Aargau – 26 June 1795) was a German botanist, a pupil of Carl Linnaeus at Uppsala University, and later director of the Botanical Garden of Hannover, where he produced several major botanical works between 1780–1793. Ehrhart was the first author to use the rank of subspecies in botanical literature, and he published many subspecific names between 1780 and 1789.
In 1779, Carl Peter Thunberg (1743-1828) named a genus of grasses, Ehrharta, in Ehrhart's honor.