"He has left Ukraine," the French embassy said, without commenting further.
Local authorities in the resort city of Odessa said earlier that Pierre Sarkozy, a 26-year-old hip-hop producer known as DJ Mosey, had been taken to hospital but that his life was not in danger.
Local media said Sarkozy had been scheduled to perform in a night club in Odessa on Tuesday, but was hospitalised under tight security after suddenly falling ill.
"It looks like food poisoning," a Ukrainian security source told AFP on condition of anonymity.
The website Dumskaya.net said a team of French doctors had flown to the Black Sea port to help the French leader's son.
The French embassy declined to provide details, saying the president's son was in Odessa on a "private visit".