It is believed the man fell from the top deck of a houseboat into the Murray River
The Department of Foreign Affairs says it is providing consular assistance to the family of an Irishman who has died in Australia.
New South Wales Police say the man - who has been named locally as Niall Quinn, aged in his mid-20s and believed to be from Co Amargh - had been on a houseboat with a group of friends when the accident occurred.
He is believed to have slipped and fallen into the Murray River, near the New South Wales border with Victoria.
It is understood he fell from the top deck of the boat, and may have hit his head during the fall.
A search was conducted by local diving and rescue units, assisted by around ten private vessels.
The body was recovered by Victoria Police divers, and a report will be prepared for the local coroner.
The Department of Foreign Affairs has said it is providing consular assistance to the man's family, who are making arrangements to travel to Australia.