La Roche-Derrien (French pronunciation: [la ʁɔʃ dɛʁjɛ̃]; Breton: Ar Roc'h-Derrien) is a former commune in the Côtes-d'Armor department of Brittany in northwestern France. On 1 January 2019, it was merged into the new commune La Roche-Jaudy.
Population
Inhabitants of La Roche-Derrien are called rochois in French.