Christian Ludwig Nitzsch (3 September 1782 – 16 August 1837) was a German zoologist. He is best remembered for his approach to classifying birds on the basis of their feather tract distributions or pterylosis of their young.
He was professor of zoology at the University of Halle. While his primary interest lay in ornithology, Nitzsch published studies on other topics, including diatoms (the diatom genus Nitzchia is named after him). He is also widely credited with producing the first systematic zoological studies of lice, Nitzsch Ch. L., Darstellung der Familien und Gattungen der Thierinsecten (insecta epizoica). Magazin fur die Entomologie, Germar, Zincken, Bd.3 (1818). In 1832, he was elected a foreign member of the Royal Swedish Academy of Sciences.