Mehmet Ali Aybar (pronounced [mehmet a?i ajba?]; 5 October 1908 – 10 July 1995) was an international lawyer, member of the Turkish parliament, the first president of the Workers Party of Turkey (Turkish: Türkiye Isçi Partisi or briefly TIP), the founder and President of the Socialist Revolution Party, and a member of the Russell Tribunal against the war crimes of the United States in Vietnam.