Peter Simon Pallas (September 22, 1741 - September 8, 1811) was a German zoologist.
In 1768 Pallas became a professor at the St Petersburg Academy of Sciences, and between 1769 and 1774 he led an expedition to Siberia collecting natural history specimens on their behalf. He explored the upper Amur, the Caspian Sea, and the Ural and Altai mountains, reaching as far eastward as Lake Baikal.
Between 1793 and 1794 he led a second expedition to southern Russia, visting the Crimea and the Black Sea.
In 1772 Pallas discovered a meteorite near to the city of Krasnojarsk. This meteorite was named Pallasite after him.
A number of animals are named after him, including Pallas Cat, Pallas's Warbler, Pallas's Gull, Pallas's Sandgrouse and Pallas's Reed Bunting.