Carl Friedrich Kielmeyer (22 October 1765 – 14 August 1844) was a German biologist and naturalist born in Bebenhausen, today part of the city of Tübingen.

He was a pioneer of Naturphilosophie, helped to establish organic chemistry (Pflanzenchemie) as a field, and developed an early version of recapitulation theory through the observation of animal embryos.

In 1816 he returned to Stuttgart as scientific director of the royal library, botanical garden, et al.

He was a prominent figure in pre-Darwinian evolutionary science, being remembered for development of an early theory of biological recapitulation--the idea that embryos pass through developmental stages that reflect their "primitive ancestors".

The plant genus Kielmeyera was named in his honor by Carl Friedrich Philipp von Martius in 1826.