Roudouallec (French pronunciation: [ʁudwalɛk]; Breton: Roudoualleg) is a commune in the Morbihan department of Brittany in north-western France.

The village lies on the southern slope of the Montagnes Noires (french, Black mountains).

Roudouallec is border by Gourin to the east, by Guiscriff and Scaër to the south, by Leuhan and Saint-Goazec to the west and by Spézet to the north.

The area around Roudouallac is represented on the Saint-Bélec slab, dating to the early Bronze Age and identified as the earliest known map that can be tied to a specific location.

[6] Nicolas Le Grand, tailor born in Roudouallec in 1852 emigrated in 1881 to the United States.