France's parliament adopted a smacking ban on Tuesday - a largely symbolic gesture in a country where there is still widespread support for corporal punishment against children.
According to France's Childhood Foundation, 85 percent of French parents admit to smacking their children.
Some conservative and far-Right members warned such legislation fostered unwanted "interference" in family life.
Once written into the Civil Code, couples who exchange marital vows will be reminded that "parental authority is exercised without physical or psychological violence".
France's penal code already bans violence against children. But under a 19th-century legal loophole, allowances have until now been made for parents' "disciplining" of children as part of "ordinary everyday violence", or what in the UK is known as "reasonable chastisement".
Previous bids to ban the practice have been blocked by conservatives but in recent years France faced accusations it was failing to change with the times.
In 2015, the Council of Europe, a rights advisory body, singled out France for failing to act.
A year later, the UN Committee on the Rights of the Child urged France to "explicitly prohibit" all forms of corporal punishment of children.
Speaking to MPs during the parliamentary debate, health minister Agnès Buzyn argued that "one doesn't educate through fear" and that such "supposedly educational" violence in fact had "disastrous consequences on a child's development".
"No violence will ever be educational, no violence is 'ordinary'," added senator Adrien Taquet.
The legislation will bring France in line with international treaties on the rights of children.
The main aim of the law is to encourage society to change its ways, said Maud Petit, the MP who sponsored the measure.
However, it remains to be seen whether the ban will change disciplinary habits in France, as it contains no specific punishment for parents who breach the rules.
Maud Petit said: "Now the hard part begins." She added that she was "deeply convinced that the French population has already evolved and already uses 'ordinary educational violence' much less".