It had been thought the gorse fire on the western section of the National Park, near Tomies Wood, had started this morning.
However, emergency services say they’ve received reports that the blaze may have started at around 9.45 last night.
An Air Corps helicopter was on standby to help fire fighters but was not needed.
The blaze was finally brought under control at around 2.45pm.
Killarney gardaí are appealing to the public to contact them at 064 663 1 222.
Up to 350 acres were burned.
Michael Hession is chief fire officer for Kerry.
Mr Hession says it’s impossible to say if the gorse fire was started deliberately.