Sumba or Soemba (both: sōōm´bä), island (1990 pop. 444,777), 4,305 sq mi (11,150 sq km), Indonesia, one of the Lesser Sundas, in the Indian Ocean, S of Flores across Sumba Strait. The chief town and port is Waingapu. The island is noted for horse breeding. Formerly Sumba was known as Sandalwood Island because of its large exports (17th–19th cent.) of sandalwood. The island was first visited by Europeans in 1522 and passed to the direct control of the Dutch in 1866.