| Sinclair Islet | |
| Settlement Type: | Island |
| Pushpin Map: | Australia |
| Pushpin Map Caption: | Sinclair Islet is located in Australia Map |
| Coordinates: | -11.108°N 143.018°W |
| Subdivision Type: | Country |
| Subdivision Name: | Australia |
| Subdivision Type1: | State |
| Subdivision Name1: | Queensland |
| Unit Pref: | US |
| Population Density Sq Mi: | auto |
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.
It is about 40 km east from Orford Ness and the Apudthama National Park.