The women claim the star groped them, put his hands in their underwear and made obscene remarks, the site said.
BBC reports the incidents are alleged to have happened over the past two decades on film and TV sets or in public places.
A lawyer for Depardieu, 74, said he "formally denies all the charges which may fall under criminal law".
The Oscar- and Bafta-nominated actor is known for films including Jean de Florette, Green Card and Cyrano de Bergerac.
The allegations come two years after he was placed under criminal investigation for rape, which he has denied.
In the Mediapart investigation, one extra on a film set said he put his hand under her dress before trying to "slip in to get to my knickers". When she pushed his hand away, he became aggressive and tried again, the woman said.
Another described how the actor "grabbed [me] by the waist" between takes, had a "wandering hand" and "ended up putting his hand on my bum in an insistent way".
One woman said he tried to "put his hand on my genitals" during a crowd scene. On another occasion, accompanied by a man he introduced as the producer, the actor allegedly grabbed her from behind and "rubbed my hips, stomach and breasts".
Many of the women told Mediapart they were shocked that no action was taken on the film sets, with his alleged behaviour being tolerated or even met with laughter.
"Adults let an actor fondle my breasts in front of everyone," said one actress, who was 17 at the time.
The Paris prosecutor's office told the AFP news agency on Wednesday it had "not received any new complaint to date".
Depardieu remains under investigation for allegedly raping an actress in 2018.
File photo. French actor Gerard Depardieu attends a press conference at the 68th Cannes Film Festival, in May 2015. Photo: AFP