Coëtlogon (French pronunciation: [kwɛtlɔɡɔ̃]; Breton: Koedlogon; Gallo: Cotlagon) is a commune in the Côtes-d'Armor department of Brittany in northwestern France.
The name Coëtlogon is typically Breton, "koad" meaning "wood" with the lieu-dit "Logon".
Inhabitants of Coëtlogon are called Logonais or Coëtlogonnais in French.