Fire fighters were called to a blaze at a single-storey barn in South Milton, Kingsbridge.
Fire control brought in two fire engines from Salcombe and Ivybridge a water bowser from Plympton and two supporting officers. A third engine was then brought in from Totnes.
When they arrived they found hay and straw well alight and crews were trying to remove approx 300 sheep from barn.
Three further fire appliances from Greenbank, Kingsbridge and Dartmouth were called in along with an incident command unit from Honiton, a welfare unit from Crediton and a further three supporting officers.
The sheep were safely removed and checked by a vet.
Around 50 per cent of the straw and bedding was damaged by fire.
One man was given oxygen following smoke inhalation and was taken to hospital as a precaution. The cause of the fire was accidental.