Yevno Azef (Russian: Евгений Филиппович (Евно Фишелевич) Азеф, 1869–1918, also transliterated as Evno Azef), was a Russian socialist revolutionary who was also a double agent working both as an organizer of assassinations for the Socialist-Revolutionary Party (also known as SRs or Esers) and a police spy for the Okhrana, the Imperial secret police. He was an agent provocateur, carrying out acts of terrorism, which justified the police's arresting his accomplices.