Frederik Ruysch (March 23, 1638 - February 22, 1731) was a Dutch doctor and anatomist, remembered for his developments in anatomical preservation and the creation of dioramas or scenes incorporating human parts.

Born in The Hague, the son of a minor government functionary. He apprenticed as an apothecary and gained his medical education at Leiden under Jan Swammerdam, graduating in 1664. He became praelector of the Amsterdam surgeon's guild the following year and also moved his new practice to Amsterdam. In 1668 he was made the chief instructor to the city's miidwives. He came to recognition amongst his peers with his proof of valves in the lymphatic system. His chief skill was in anatomy and also in the preparation and preservation of specimens. In 1679 he was appointed as a forensic advisor to the Amsterdam courts. Lecturer in botany at a minor Amsterdam educational establishment, the Anteneum Illustre.

He built up a "repository of curiosities" and later sold it to Peter the Great for a reported 30,000 guilders. He immediately began anew and this collection was sold to another royal after his death. While some of his preserved collections remain none of his scenes have survived, they are only known through a number of engravings, notably those by Cornelius Huyberts.