At around 9.30pm IST last night, emergency services were called to Fanore Beach to assist two people swimming.
One swimmer made it to shore, but the other remained in the water.
The Irish Coast Guard Rescue 115 Helicopter was dispatched from Shannon to assist, as were the Doolin Coast Guard and the Aran Islands RNLI.
The man was flown to Galway University Hospital and later pronounced dead.