The practice of smacking children, referred to in France as la fessée is condemned by the UN but still enjoys widespread support in the country
The ban, to be put to a final vote in the Senate on Tuesday, would make France the 55th state to prohibit corporal punishment of children.
It will be written into the Civil Code and read out to couples when they exchange their marital vows.
The newly-weds will be told that “parental authority is exercised without physical or psychological violence”.
The measure, which was adopted by MPs in November, is expected to easily pass the Senate despite some lawmakers on the right railing against what they see as “interference” in family life.
Violence towards children is already banned under France's penal code, but a 19th-century addendum to the Civil Code's definition of parental authority made allowances for parents when “disciplining” their children.
According to France's Childhood Foundation, 85 percent of French parents admit to smacking their children.
Attempts by previous governments to ban the practise have run afoul of conservatives, but resistance has softened in recent years.
The new law does not contain a specific punishment for parents who break the rules.
Its main goal is to encourage society to change its ways, Maud Petit, the MP who sponsored the measure, said.
The legislation will bring France in line with international treaties on the rights of children.
In 2015, the Council of Europe, which makes recommendations on rights, singled out France for failing to follow the example of other European countries by banning smacking.
A year later, the UN Committee on the Rights of the Child urged France to “explicitly prohibit” all forms of corporal punishment of children.