Gapuwiyak is on the shore of Lake Evella in north-east Arnhem Land, about 500 km east of Darwin and 120 km west of Nhulunbuy. It is one of the Northern Territory's eastern most settlement.
The Population of Gapuwiyak and its surrounds in 2011 was approximately 874, of which 824 were indigenous (94 per cent). In 2011, 40 per cent of Gapuwiyak's Indigenous population was younger than 20 years of age.
Djambarrpuyngu (a dialect of Yolngu Matha) is the main language in Gapuwiyak, spoken by 76 per cent of people. Other languages include Ritharrngu and Dhalwangu.