Donoussa is found 9n.m. east of Naxos and 14n.m. north of Amorgos and it belongs to the complex of the East Small Cyclades.
It is 13.6km2. The length of the coastline is no more than 31km.
The terrain is rocky, semi-mountainous, with Papos hill (385m) being the highest point.
The coasts show intense fragmentation, creating precipitous capes and successive coves many of whom form quiet beaches with fine sand.
Up to the first years of the 20th century the residents mainly dealt with the cultivation of tobacco. In the Interwar years they made excavations of copper, calamine and indigo. Today their main occupations are cattle breeding, fishing and tourism.
On the island there is maquis plantation, which is low due to the winds. Pistacia plants, cedars, brushwood, thyme etc. thrive. Two rare species of orchids (Ophrys iricolor and Ophrys dodekanensis) have been identified here as well.
The entire island of Donoussa is considered an important area for the migratory birds, endemic species and the marine life i.e. the Mediterranean monk seal, the crow, Eleonora's falcon, and 5 species of lizards of the genus Cyrtodactylus.