The name comes from theBreton wordPlou and the nameCadoc, a Breton saint, meaningParish of Cadoc. Numerousmegaliths are to be found around the commune.
Pleucadeuc is located in the natural region of the Landes de Lanvaux, 19 km (12 mi) south ofPloërmel, 31 km (19 mi) northeast ofVannes and 74 km (46 mi) west ofRennes.
Pleucadeuc holds an annualfestival on 15 August for pairs oftwins and multiples calledrassemblement "Deux et plus" ("the Two and more" gathering"). This festival started in 1994 and has become France's largest annual gathering of twins, with approximately 1,000 sets attending each year, and one of the largest such events in Europe.