The Betar Movement (Hebrew: תנועת בית"ר), also spelled Beitar (בית"ר), is a Revisionist Zionist youth movement founded in 1923 in Riga, Latvia, by Vladimir (Ze'ev) Jabotinsky. Chapters sprang up across Europe, even during World War II. After the war and during the settlement of what became Israel, Betar was traditionally linked to the original Herut and then Likud political parties of Jewish pioneers. It was closely affiliated with the pre-Israel Revisionist Zionist paramilitary group Irgun Zevai Leumi. It was one of many right-wing movements and youth groups arising at that time that adopted special salutes and uniforms. Some of the most prominent politicians of Israel were Betarim in their youth, most notably prime ministers Yitzhak Shamir and Menachem Begin, an admirer of Jabotinsky.

Today, Betar promotes Jewish leadership on university campuses as well as in local communities. Its history of empowering Jewish youth dates back to before the establishment of the State of Israel. Throughout World War II, Betar was a major source of recruits for both the Jewish regiments that fought the Nazis alongside the British and the Jewish forces that waged an ongoing guerrilla war against the British in Palestine. Across Europe, Betar militias played major roles in independently resisting Nazi forces and their various assaults on Jewish communities.