It is situated on the main expressway RN165 fromNantes toBrest, adjoining the city ofVannes by the west. The village is very close to theGolfe du Morbihan, and is bordered byPlescop to the north, byPlougoumelen to the west, byBaden, byArradon to the south and by Vannes to the east.
Ploeren's territory is 20.44 km2, and there were 6,284 inhabitants in 2013.
The former mayor, Corentin Hilly, invented a new type of traffic lane named “Voie 2M”, which consists in two separate lanes; the first one is a normal road for engine vehicles, and the second one is for all ways of moving without an engine, like riding a bicycle or walking.
The current mayor is Gilbert Lorho who was elected in 2014.