Sinclair Islet is a small island north of Shelburne Bay in far north Queensland, Australia about 150 km north of Cape Grenville, Cape York Peninsula in the Great Barrier Reef Marine Park Queensland, Australia.

Sinclair Islet
Sinclair Islet is located in Australia
Sinclair Islet
Sinclair Islet
Sinclair Islet is located in Australia Map
Coordinates: 11°06′29″S 143°01′05″E / 11.108°S 143.018°E / -11.108; 143.018
CountryAustralia
StateQueensland

It is about 40 km east from Orford Ness and the Apudthama National Park.