Petr Petrovich Sushkin (Russian: Петр Петрович Сушкин; 27 January 1868 – 17 September 1928) was a Russian ornithologist. He was born in Tula, Russia, and studied in Moscow before joining the staff of the Leningrad Zoological Museum in 1898, remaining there until his death. He studied birds in southeastern Russia, Siberia and the Altai Mountains. He published in English, German, and Russian, and wrote Notes on systematics and distribution of certain palaearctic birds, an influential article on bird relationships.