The Scottish Fire and Rescue Service (SFRS) said four appliances were at the scene after responding to reports of the fire at 6.38pm.
A SFRS spokesperson said: “We were alerted at 6.38pm on Sunday, 19 July to reports of a fire in the open at Arthur’s Seat in Edinburgh.
“Operations Control mobilised four fire appliances and crews are still at the scene.
“There are no reported casualties.”
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It is the second blaze at the Scottish landmark in the last three months.
In May, firefighters battled a large grass fire in Holyrood Park near Arthur’s Seat, with no injuries reported.
The fire on Sunday evening came as the SFRS continued to battle a wildfire in the Cairngorms national park, which has been burning since Wednesday.
