Saint Giles Island is the largest in a group of small islands off the north-eastern tip of Tobago, in the Caribbean country of Trinidad and Tobago.

The island is very steep sided and hosts tropical dry forest and wind-swept littoral scrub. At least five species of reptiles have been recorded for the island. One is a snake - Boddaert's tropical racer. The remaining four are lizards - green iguanas, turnip-tailed geckos, eyespot geckos and an unidentified species of skink in the sub-family Mabuyinae.

Saint Giles, along with adjacent rock islets, has been designated an Important Bird Area (IBA) by BirdLife International because it supports significant populations of red-billed tropicbirds, Audubon's Shearwaters and magnificent frigatebirds, as well as red-footed, brown and masked boobies. It is one of the most important seabird breeding islands in the southern Caribbean.

• Islands of Trinidad and Tobago

11°21′N 60°31′W / 11.350°N 60.517°W / 11.350; -60.517