The Cap d'Agde resort in the Hérault region, hugely popular among naturists, saw 38 positive tests on Monday and another 57 on Wednesday, the regional health authority said.
The rate of infection was four times higher among naturists in the resort than in the village itself, it added. Another 50 holidaymakers had also tested positive after returning home and results of more tests were expected next week.
The figures are “very worrying” it said, adding an alert had been issued over the resort.
The outbreak comes as France on Sunday reported almost 4,900 new coronavirus cases over the last 24 hours, its highest figure since May, as the health minister acknowledged there were “risks” in the surging infection levels nationwide.