Concarneau (Breton: Konk-Kerne, meaning "Bay of Cornouaille") is a commune in the Finistère department of Brittany in Northwestern France.

In August the town holds the annual Fête des Filets Bleus (Festival of the blue nets).

The festival, named after the traditional blue nets of Concarneau's fishing fleet, is a celebration of Breton and pan-Celtic culture.

Such festivals can occur throughout Brittany but the Filets Bleus is one of the oldest and largest, attracting in excess of a thousand participants in traditional dress with many times that number of observers.

Concarneau was the setting for Belgian mystery writer Georges Simenon's 1931 novel Le Chien jaune (The Yellow Dog), featuring his celebrated sleuth Maigret.