Perpignan, near the Spanish border, has become the latest city to issue fines to people who refuse to cover up after being approached by the police.
The move comes after Cavaillon in Provence brought in a similar law this year, the Independent reports.
The fines, which have been in place in Cannes and St Tropez for many years, can reach up to Â£31.
The laws were brought in by councils in inland cities after locals complained over the rising number of visitors parading around the streets in little more than shorts or skimpy swimwear.
In Perpignan, citizens were shocked to see British rugby fans strip off to their bare chests while visiting the city for a recent match.
â€œWeâ€™re not saying thereâ€™s been a general moral decline, but some people have complained,â€ the cityâ€™s security chief told Le Midi.
The new law calls for â€œhuman dignity, decency, morality and protection of the young.â€
The squeamishness has already spread to Paris, where â€œdecency of dressâ€ is mandatory.