The ban was proposed as an amendment to Health Minister Marisol Touraine’s health reform package by Socialist MP and neurologist Olivier Véran.
Touraine herself backed the proposal that would stop model agencies being able to employ models whose Body Mass Index (BMI) falls below a certain level.
Agencies found employing models considered too thin could be liable for a fine of up to 75,000 euros ($85,000) and six months in prison.
The lower house of parliament also backed a law making a "retouched photo" tag compulsory when people's bodies in commercial images are Photoshopped.
The aim, the Socialist deputies sponsoring the measures said, is to bring body ideals hawked to the public back to a healthy reality.
"The prospect of such a punishment will have the effect of regulating the entire sector," said Véran, noting that similar measures had been taken in Spain, Italy and Israel.
Health Minister Marisol Touraine had previously said that young models should "eat well and look after their health".
"This is an important message to young women who see these models as an aesthetic example," added the minister.
But France's National Union of Modelling Agencies, or SYNAM, slammed the move for "lumping together anorexia and thinness."
It noted that some models were naturally very slim and could argue they were being discriminated against by the measure.
"When you look at the criteria behind anorexia, you can't look only at the body mass index when other criteria are also involved: psychological, a history of hair loss, dental problems," the head of SYNAM, Isabelle Saint-Felix, complained to AFP.
"It's important that the models are healthy," she said, "but it's a little simplistic to think there won't be any more anorexics if we get rid of very thin models."
The union warned the competitiveness of French modelling could be undermined by the proposed laws. Saint-Felix said nine out of ten models used in French fashion shows and magazines were foreign.
France's ruling Socialists, however, appear determined to bring legislative oversight to the sector.
The other amendment voted on Friday, calling for Photoshopped images to be declared as such, focused on manipulations to make models' bodies in ads look thinner — or, in cases of ultra-thin models, thicker.
The penalty for breaking the proposed law could run to a fine of either €37,500 or 30 percent of the budget behind the offending advertising campaign.
The draft law was aimed at commercial images and would not affect other representations such as artistic photos.
The amendments comes after French lawmakers approved another amendment proposed by Véran that would punish people inciting others to "extreme thinness" to a year in prison and a fine of €10,000.
That law was aimed at so-called "pro-ana" websites that some accuse of encouraging anorexia.
The votes come two weeks after both of Véran’s amendments were rejected by a parliamentary commission with lawmakers claiming that banning skinny models would lead to discrimination in the hiring process.
Up to an estimated 40,000 people suffer from anorexia in France, nine out of ten of them women and girls.