Peter Ascanius (Aure, 1723–1803) was a Norwegianbiologist and a student of Linnaeus. He taught zoology and mineralogy in Copenhagen from 1759 to 1771, and later worked as a supervisor at the mines in Kongsberg and elsewhere in Norway. Among his published works was the five-volume illustrated Icones rerum naturalium. He was a Fellow of the Royal Society, elected in 1755 as a Foreign Member.
Ascanius first discovered the giant oarfish in 1772.