Simon bar Kokhba (died CE 135) is the Jewish leader of what is known as the Bar Kokhba revolt against the Roman Empire in 132 CE, establishing an independent Jewish state of Israel which he rules for three years as Nasi ("Ruler").

His state is conquered by the Romans in 135 following a two-year war.

Documents discovered in the modern era give us his original name, Simon ben Kosiba, he was given the surname Bar Kokhba, (Aramaic for "Son of a Star", referring to the Star Prophecy of Numbers 24:17, "there shall step forth a star out of Jacob, and a scepter shall rise out of Israel, and shall smite through the corners of Moab") by his contemporary, the Jewish sage Rabbi Akiva.

After the failure of the revolt, the rabbinical writers referr to bar Kokhba as "Simon bar Kozeba" (Hebrew: "Son of lies" or "Son of deception").