Sumba, also known by the native spellings Humba, Hubba, Suba, or Zuba, is an Indonesian island located in Eastern Indonesia. It is administratively part of the East Nusa Tenggara provincial territory. The island covers a land area of 10,909.55 square kilometres, which is approximately the same size as Jamaica or the island of Hawaii.
The population of Sumba was recorded at 686,113 during the 2010 Census and grew to 779,049 by the 2020 Census, with a mid-2025 estimate of 852,832. Geographically, the island is situated northwest of Sumbawa, northeast of Flores across the Sumba Strait, and east of Timor across the Savu Sea. To its south lies Australia across part of the Indian Ocean.