The H5N8 strain of avian influenza has been discovered in County Wexford.
The Department of Agriculture has confirmed H5N8 has been identified in a wild duck.
The Health Protection Surveillance Centre says no human infections of the disease have been reported worldwide.
In the last fortnight bird flu has been identified on a number of UK farms - while Minister Michael Creed last week issued an order that all poultry be kept indoors in a bid to prevent the spread of the disease.
Several European countries including Germany, Poland and Denmark have confirmed cases of H5N8 since it was discovered in a wild swan in Hungary on 27 October.