The Barat Daya Islands (; ) are a group of islands in the Maluku province of Indonesia, with an estimated 100,000 inhabitants in 2026. The Indonesian phrase barat daya means 'south-west'.
Geography
These islands are located off the eastern end of East Timor. Wetar is the largest island in the group. To the west, the Ombai Strait separates Wetar from Alor Island, part of East Nusa Tenggara. The Wetar Strait separates Wetar from Timor to the south.
Even though included in the Indonesian Maluku province political division, the southwestern islands are geographically part of the Lesser Sunda Islands. Rainfall is limited with a dry season between October and December when some of the islands appear as dry savannah. The Barat Daya Islands except Wetar are part of the Banda Sea Islands moist deciduous forests ecoregion. Wetar and Timor comprise the Timor and Wetar deciduous forests ecoregion. Most of the islands are barren, infertile and minimally forested.
The districts are formally grouped into three archipelagoes – the Terselatan Group (including Wetar, as well as Kisar and Romang Islands), the Lemola Group (Letti, Moa and Lakor) and the Babar Group (including the Damer and Sermata Islands). The areas (in km<sup>2</sup>) and the populations at the 2010 census and 2020 census, together with the official estimates as at mid 2025,