Sule Skerry lies 60 kilometres (32 nautical miles) west of the Orkney Mainland at grid reference HX621244.

[8] The island is treeless, since few trees would withstand the high winds of winter and salt spray environment.

Since the first visiting birds in 2003 there is now a large breeding population of gannets; a possible overflow from nearby Sule Stack.

The island (along with Sule Stack) has been designated an Important Bird Area (IBA) by BirdLife International because it supports breeding populations of several species of seabirds.

A meteorological buoy used in Met Office's Marine Automatic Weather Station (MAWS) Network is located off Sule Skerry.