It lies about 1.5 kilometres (0.93 mi) north of Hamars Ness on Fetlar, south of Unst, and to the east of Yell.
Gruney means a "green island", and "sound" refers to the strait.
Sound Gruney's maximum elevation is about 9 metres (30 ft) above sea level.
The latter is 1 km north of Urie Ness on Fetlar,[1] hence the name.
Wedder Holm, south of Uyea, is to the north east.