Under the new bill, prostitutes' clients will become offenders while soliciting itself will no longer be considered a criminal offence.
Previously, buying and selling sex for money was not illegal in France but the act of soliciting was, as was pimping.
The reform, which has divided the country, still needs to be formerly endorsed by parliament on Wednesday.
Movie stars like Catherine Deneuve, who played a middle-class housewife who chooses to prostitute herself in the 1960s film "Belle de Jour", is one of several dozen celebrities who have signed a petition against the law.
Some 90 percent of France's estimated 20,000 to 40,000 prostitutes are foreign, mostly victims of Nigerian, Chinese and Romanian trafficking networks, the government says.
That is a very different picture from just over a decade ago, when only one in five prostitutes were foreign and organized crime rings much less prevalent - one of the main reasons the law needs tightening, proponents say.