Priziac (French pronunciation: [pʁizjak]; Breton: Prizieg) is a commune in the Morbihan department of Brittany in north-western France.

The commune's population has been divided by three within a century because of rural exodus.

Near the village centre is the Bel Air lake, with an area of 54 hectares.

It was besieged unsuccessfully by the troops of Walter of Mauny during the War of the Breton Succession Guy Éder de La Fontenelle, a nobleman at the head of a band of 400 riders, seized the fortified castle of Cremenec, in Priziac, on 10 February 1595.

The first mayor of Priziac, Jean Le Roux, was murdered by a band of chouans in his house in the village of Kerveno, on 23 December 1794.