The area affected is believed to be Whitley Woods in Lepton, and smoke can be seen from Emley Moor.
Around 300x200 metres of dense vegetation is on fire and the terrain has been described as difficult to access.
West Yorkshire Fire and Rescue Service have sent five crews to the scene as well as two specialist wildlife units from Todmorden and Keighley. A specialist wildlife officer is also present.
Local farmers are also providing assistance.
Large areas of Yorkshire are subject to the most severe level of fire risk due to the exceptionally dry spring weather.
People have been reminded not to have barbecues or light fires in the countryside, and not to dispose of cigarette ends on the ground.
In Doncaster, a fire on the peat moorland at Hatfield Moors has now been burning for around two weeks.