Friedrich Ernst Ludwig Fischer (20 February 1782, Halberstadt – 17 June 1854) was a Russian botanist, born in the Holy Roman Empire.

In 1804 he obtained his medical doctorate from the University of Halle, afterwards working as director of Count Razumoffsky's botanical garden in Gorenki (near Moscow).

In 1823, he was appointed director of the imperial botanical garden in St. Petersburg by Alexander I.

Here, he was involved with establishing a herbarium and library, as well as the planning of numerous scientific expeditions into the interior of Russia.

During his final years, he served as a medical councillor for the Ministry of the Interior.