The 19-year-old had jumped into the water by the foot of the Saint-Bénezet bridge in the town for a refreshing dip at around 6:45pm on Wednesday, Europe1 reported.
However the teenager was reportedly not a good swimmer and was dragged down by a current in front of his wife and two friends, who were on holiday with him.
Paramedics were unable to revive the teenager, who was discovered six metres below the surface.
The man's companions were due to return to South Korea on Thursday.
The Local reported last week how a British father of four died in a freak accident at Labenne beach in south west France after reportedly breaking his back diving into a huge wave, that led to him drowning.
Earlier this month, a British expat died in a lake at the campsite in Marandan, in the Isere region of south east France.