A barn containing around 300 bales of hay is ablaze on the Revallagh Road, between Coleraine and Bushmills.
A massive smoke plume is visible for miles.
In a statement to Causeway Coast Community a NIFRS spokesperson said: "SIX fire appliances are currently at the scene. 2 from Coleraine Fire Station, 2 from Portrush Fire Station, 1 from Dungiven Fire Station and 1 from Ballymoney Fire Station.
The incident is ongoing"