A communications mast in Hollyhill was on fire late last night.
The mast is located in Ardcullen.
The cause of the fire was under investigation but was believed to have been malicious.
Fire brigade personnel from Cork City Fire Service attended the scene after 11pm.
The incident follows two fires at a mast in Letterkenny in Donegal in recent weeks.
The investigation into those fires was probing whether they were related to conspiracy theories about a link between 5G and Covid-19.
Local resident, Sinn Fein's councillor Mick Nugent, was alerted to the incident by a neighbour.
He said fire personnel at the scene had the situation under control fairly quickly.
Mr Nugent said his concern "was for local residents in the area if the fire had got out of control and had threatened the stability of the structure".