Kevin Sinnott, son of former Irish Member of the European Parliament (MEP) Cathy Sinnott, drowned in a lake in the Gold Creek Golf Course area of Dawsonville, Georgia.
The 22-year-old was a final year student at the nearby Southern Catholic College.
Dawson County Emergency Service chief Lanier Swafford told AP that Sinnott was in a group of six students who went for a swim on Monday night.
"Kevin got in trouble, and they attempted to help him get back to shore," said Swifford.
A body was recovered on Tuesday evening about 15 feet off shore.
Kathy Sinnott, a native of Chicago, arrived in the U.S. on Tuesday night and is being assisted by the New York Consulate. Sinnott was an Independent MEP for Munster, but lost her seat in the 2009 election.
South Eastern states have been rocked by floods over the past few days, and seven people have died as a result of the heavy rains.