The canton of Cherbourg-en-Cotentin-3 (before March 2020: canton of Cherbourg-Octeville-3) is an administrative division of the Manche department, northwestern France. It was created at the French canton reorganisation which came into effect in March 2015. Its seat is in Cherbourg-en-Cotentin. It consists of the following communes: 1. * Cherbourg-en-Cotentin (partly) 2. * Couville 3. * Hardinvast 4. * Martinvast 5. * Nouainville 6. * Saint-Martin-le-Gréard 7. * Sideville 8. * Teurthéville-Hague 9. * Tollevast 10. * Virandeville