It is the latest accusation against the Polish-born director who fled to France in 1978 from the US after admitting the statutory rape of a 13-year-old girl.
The 86-year-old has been a fugitive ever since from the US justice system, despite repeated attempts to have him extradited.
Valentine Monnier told Le Parisien newspaper that the alleged rape occurred in 1975 when she was 18 at Polanski's chalet in Gstaad.
“I had no links with him, neither personal nor professional, and hardly knew him,” Monnier, a former model who worked in New York, said.
She said the alleged rape was “extremely violent”, adding: “He pummelled me until I gave in and then raped me, making me do all sorts of things.”
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Monnier, who acted in a few films in the 1980s, said she had finally decided to speak out as Polanski's new film about an error of justice was due to come out.
Following the Harvey Weinstein scandal Monnier said she had written letters about the alleged rape to Los Angeles police and to French first lady Brigitte Macron.
Polanski's lawyer Herve Temime said the director “firmly denies all accusations of rape,” adding that the allegations “which date back 45 years have never been reported to judicial authorities”.
Polanski has also been accused of sexual assault by others. In 2010, British actress Charlotte Lewis accused him of “sexually abusing” her in 1983 when she was 16.
Another woman, identified only as Robin, accused him in August 2017 of sexual assault when she was 16 in 1973.
In September 2017, former actress Renate Langer filed a new complaint alleging she had been raped by Polanski in 1972 when she was 15.
Polanski's lawyer said all three allegations were baseless.
Polanski, who directed “Rosemary's Baby” and “Chinatown”, was accused of drugging a 13-year-old girl before raping her at film star Jack Nicholson's house in Los Angeles in 1977.
He admitted statutory rape after a number of more serious charges were dropped, and spent 48 days in custody to undergo psychiatric evaluation before being released.