| Quémènès | |
| Native Name: | Kemenez |
| Native Name Lang: | br |
| Coordinates: | 48.3736°N -4.8994°W |
| Location: | Iroise Sea, Celtic Sea, North Atlantic Ocean |
| Archipelago: | Molène Archipelago |
| Area Km2: | 0.3 |
| Length Km: | 1.6 |
| Width Km: | 0.4 |
| Coastline Km: | 3.42 |
| Elevation M: | 13 |
| Country: | France |
| Country Admin Divisions Title: | Region |
| Country Admin Divisions: | Brittany |
| Country Admin Divisions Title 1: | Department |
| Country Admin Divisions 1: | Finistere |
| Country Admin Divisions Title 2: | Commune |
| Country Admin Divisions 2: | Le Conquet |
| Population: | 3 |
| Population As Of: | 2023 |
| Languages: | French |
| Timezone1: | CET |
| Utc Offset1: | +1 |
| Timezone1 Dst: | CEST |
| Utc Offset1 Dst: | +2 |
| Website: | quemenes.bzh |
Quémènès or Quemenes (French: Île de Quémènès; Breton: Kemenez) is an island in the Molène Archipelago in the Atlantic off Brittany, France. As of 2023, it has a population of 3. It is administered as part of the commune of Le Conquet, St-Renan Canton, Brest Arrondissement, in Finistère Department.
In 1292, two sailors, one Norman and one Bayonnais, quarreled over who would draw water from a well on the island first. The dispute ended in murder, probably of the Norman, and other Norman and French sailors began to assault Aquitainian & English shipping and ports. This eventually escalated into the 1294–1303 Gascon War, which ended in a general return to the Latin: [[status quo ante bellum|status quo]] but whose financing provoked a clerical crisis leading to the Avignon Papacy and whose settlement terms produced the marriage leading to the Hundred Years' War.
Quémènès lies 2nmi from Molène, the chief island of the archipelago.