French naturalist and physician who contributed substantially to zoology by his descriptions of marine animals, primarily of the Mediterranean Sea.

Rondelet's book, Libri de Piscibus Marinis (1554–55; “Book of Marine Fish”), contains detailed descriptions of nearly 250 kinds of marine animals with nearly the same number of illustrations. He included, in addition to fishes, whales, marine invertebrates, and seals, regarding them all as fishes. As professor of anatomy at the University of Montpellier and physician to a cardinal, Rondelet also wrote extensively on fever, diagnosis, and the preparation of medicinal drugs.