Firefighters said the blaze lasted for hours on Tuesday after it broke out on the moorland.
Paul Slaven, a spokesperson for Devon and Somerset Fire and Rescue Service , told The Independent four hectares of land covered in gorse had been damaged by the wildfire at Dartmoor.
It was briefly declared a major incident, he added.
The fire service said the blaze - which started around 4.15pm - was accidental.
“We have six fire appliances plus special appliances at a large gorse fire on Dartmoor,” Devon and Somerset Fire and Rescue Service wrote on social media on Tuesday afternoon.
“Firefighters are using beaters to prevent the fire spreading.”
It said the fire was at Mary Tavy - a village on the western edge of Dartmoor - and caused road closures on a main road between Tavistock to Okehampton.
“Fire front of approximately 750m, firefighters using beaters and wildfire vehicles to prevent fire jumping the A386,” the fire service said a couple of hours later.
The blaze was under control at around 9pm, Mr Slaven from the local fire and rescue service said.
He said it was the third gorse fire that firefighters had been called out to in a week, following one on Exmoor on Friday and another on Dartmoor last week.