Pieter Johannes Veth (2 December 1814 in Dordrecht - 14 April 1895 in Arnhem) was a Dutch professor of geography and ethnology and the first Chairman of the Royal Netherlands Geographical Society.
He was also the father of Daniël David Veth, a Dutch explorer and photographer.
He was professor of Ethnology of the Dutch East Indies in Leiden from 1864 to 1876 and extraordinary professor of history, literature, antiquities, institutions, manners and customs of the peoples the Indian archipelago and physical geography of the Indonesian archipelago at Leiden University from 1877 to 1885.
He was the first chairman of the 1873 established Koninklijk Nederlands Aardrijkskundig Genootschap (Royal Dutch Geographical Society, KNAG) and was chairman of the Vereeniging tot Nut van 't Algemeen.
The building Nonnensteeg of the Faculty of Arts of Leiden University was renamed the P.J.