The tropical island of Wetar belongs to the Indonesian province of Maluku and is the largest island of the Barat Daya Islands (literally Southwest Islands). It lies east of the Lesser Sunda Islands, which include nearby Alor and Timor, but it is politically part of the Maluku Islands.
To the south, across the Wetar Strait, lies the island of Timor; at its closest it is 50 km away. To the west, across the Ombai Strait, lies the island of Alor. To the southwest is the very small island of Liran, which is also part of Wetar district (kecamatan) and, further southwest, the small East Timorese island of Atauro. To the north is the Banda Sea and to the east lie Romang and Damar Islands, while to the southeast lie the other principal islands of the Barat Daya Islands.
The principal towns on Wetar are Lioppa in the northwest, Ilwaki in the south, Wasiri in the north, Masapun in the east, and Arwala in the northeast. These are connected by roads.