Bolshoi Tyuters (Russian: Большой Тютерс; Finnish: Tytärsaari; Estonian: Suur Tütarsaar; Swedish: Tyterskär) is an island in the Gulf of Finland of the Baltic Sea, located 75 km away from the coast of Finland, to the south-east from Hogland. The island is a part of the Leningrad Oblast, Russia. The area is approximately 8.3 km².