The fire broke out in a house in Co Kerry, in a village called Moyvane at around 11pm Monday night.
Firefighters from the Limerick fire service battled the blaze for four hours, and the elderly man was pronounced dead at the scene by medics.
Gardai were on the scene then to begin an examination, noting that neighbouring houses in Woodgrave housing estate were damaged by the spreading fire.
The body of the deceased was transported to Tralee to University Hospital Kerry where the post mortem will be taking place.
As of now, the fire is not believed to be caused by suspicious acitivity.