Fanny Efimovna Kaplan (Russian: Фа́нни Ефи́мовна Капла́н; real name Feiga Haimovna Roytblat, Фейга Хаимовна Ройтблат; February 10, 1890 – September 3, 1918) was a Ukrainian Jewish woman, Socialist-Revolutionary, and early Soviet dissident. She was arrested for the attempted assassination of Vladimir Lenin and was executed by the Cheka in 1918.

As a member of the Socialist Revolutionary Party, Kaplan viewed Lenin as a "traitor to the revolution" when the Bolsheviks enacted one-party rule and banned her party. On August 30, 1918, she approached Lenin, who was leaving a Moscow factory, and fired three shots, which badly injured him. Interrogated by the Cheka, she refused to name any accomplices and was executed. The Kaplan attempt and the Moisei Uritsky assassination was used by the government of Soviet Russia for the reinstatement of the death penalty, which had been abolished by the Russian Provisional Government in March 1917.