| Île Aganton | |
| Map: | France Côtes-d'Armor |
| Location: | English Channel |
| Coordinates: | 48.7986°N -3.5958°W |
| Length M: | 1000 |
| Width M: | 500 |
| Country: | France |
| Country Admin Divisions Title: | Region |
| Country Admin Divisions: | Brittany |
| Country Admin Divisions Title 1: | Department |
| Country Admin Divisions 1: | Côtes-d'Armor |
| Country Admin Divisions Title 2: | Arrondissement |
| Country Admin Divisions 2: | Lannion |
Île Aganton is an island on the north coast of Brittany (France), adjacent to Île-Grande which is to the east. Its size is about 1 km west to east, and it has a maximum width of about 500 m.[1] It is accessible on foot at low tide. It is in the commune of Pleumeur-Bodou (department of Côtes-d'Armor).
On the coast, Trébeurden lies to the south, and Trégastel to the east.
There is no permanent habitation. Dunes cover much of the island; there is heather, and a small pine wood planted in 1920. There are two stone crosses, indication possibly of a burial ground from former times.[1]
The island has three branches; at the ends of each branch there is evidence of past granite-quarrying. The main site of former activity is on the north-east branch, where there is the largest quarry on the island, ruined buildings, and a jetty for loading boats at high tide.[1]