| Juan Guillermos Island | |
| Native Name: | Isla Juan Guillermo |
| Map: | Tierra del Fuego |
| Coordinates: | -52.1667°N -74.1667°W |
| Waterbody: | Pacific Ocean |
| Area Km2: | 393 |
| Country: | Chile |
| Country Admin Divisions Title: | Region |
| Country Admin Divisions: | Magallanes |
| Country Admin Divisions Title 1: | Province |
| Country Admin Divisions 1: | Última Esperanza |
| Country Admin Divisions Title 2: | Commune |
| Country Admin Divisions 2: | Puerto Natales |
| Additional Info: | NGA UFI=-885433 |
Juan Guillermos Island (also known as Isla Esmeralda) is a Chilean island in the Queen Adelaide Archipelago in Magallanes and Antártica Chilena Region. It is named after the English Captain John Williams Wilson.[1]
It is located north of Cochrane Island, south-west of Barros Arana and Pedro Montt Islands.