Gallo is a regional language of eastern Brittany. It is one of the langues d'oïl, a Romance sub-family that includes French. Today it is spoken only by a minority of the population, as the standard form of French now predominates in this area.

Brittany is a peninsula, historical country and cultural area in the north-west of modern France, covering the western part of what was known as Armorica during the period of Roman occupation. It became an independent kingdom and then a duchy before being united with the Kingdom of France in 1532 as a province governed as a separate nation under the crown.