Gerardus Troost (March 5, 1776 – August 14, 1850) was a Dutch-American medical doctor, naturalist, mineralogist, and founding member and first president of the Philadelphia Academy of Natural Sciences.

After a brief practice at Amsterdam and the Hague, he was enlisted in the army as a private soldier, and then as an officer of the first class in the medical department.

While in Paris, he translated into the Dutch language one of the earlier works of Alexander von Humboldt, The Aspects of Nature.

[5] Troost is credited with describing, as new species, two North American reptiles: the alligator snapping turtle (Macrochelys temminckii) and the western cottonmouth (Agkistrodon piscivorus leucostoma).

This article incorporates text from this source, which is in the public domain: Bonnier Corporation (June 1894).