People will be allowed to move around La Marina, in the province of Lugo, but the only people allowed to enter or leave will be those who need to travel for work.
Those in the area will still be able to move around freely, and facilities such as restaurants can remain open in a limited capacity.
Face masks will also be mandatory at all times, and the lockdowns are being enforced by police road blocks, Spanish media reports.
Coronavirus cases in Galicia have risen to 258, regional health authorities have said, of which 117 were in Lugo.
Spain’s Prime Minister, Pedro Sanchez, speaking at a political rally ahead of regional elections in Bilbao on Sunday, urged people not to lower their guard and to stay calm.