The Socialist Unity Party (Turkish: Sosyalist Birlik Partisi, abbreviated SBP) was a political party in Turkey. The party was founded on January 15, 1991. It was headed by Sadun Aren, a former university professor.[2] The party was largely a successor organization of the banned United Communist Party of Turkey (TBKP).[3] SBP held its first party congress in Ankara in May 1992.[4]