Johann Friedrich von Eschscholtz (1 November 1793 – May 1831) was an eminent botanist, physician and naturalist.
Eschscholtz was a Baltic German; he was born and died in Tartu (then Dorpat) in what is now Estonia, studied medicine at the local University of Tartu, and spent his main career there as well: extraordinary professor of anatomy (1819), director of the zoological cabinet (1822), professor of anatomy 1828.
Eschscholtz is famous for his participation in the two circumnavigations by the globe by Otto von Kotzebue, 1815 - 1818 and 1823 - 1826, where he was the ship's physician and one of the scientists. He was one of the first and most important scientists in the exploration of the Pacific, Alaska, and California. Among his publications were the System der Akalephen (1829), and the Zoologischer Atlas (1829 - 1833). Eschscholtz was the first naturalist to describe the acorn worm (Balanoglossus), which he encountered in the Marshall Islands in 1825.
Kotzebue named an island in the Marshall Islands as Eschscholtz Atoll. This was renamed in 1946 to Bikini Atoll. The botanical genus Eschscholtzia (California Poppy) was named by the German romantic poet and scientist Adelbert von Chamisso in his honour.