Plouguenast (French pronunciation: [pluɡna]; Breton: Plougonwaz; Gallo: Ploegenas) is a former commune in the Côtes-d'Armor department of Brittany in northwestern France.

The average annual rainfall is 966.8 mm (38.06 in) with January as the wettest month.

The temperatures are highest on average in August, at around 17.5 °C (63.5 °F), and lowest in January, at around 5.3 °C (41.5 °F).

Inhabitants of Plouguenast are called plouguenastais in French.

This Côtes-d'Armor geographical article is a stub.