By Agence France-Presse
The lawsuit by Julie Roginsky, a political strategist who was a contributing commentator, came eight months after Ailes, a confidant of the cable network's founder Rupert Murdoch, was forced out over an earlier harassment suit.
Monday's complaint filed in New York state court said Ailes repeatedly made sexual advances and inappropriate comments to Roginsky.
It said Ailes often looked down Roginsky's dress and made clear his sexual intentions during their meetings, and that when she rebuffed him, he refused to give her a promised hosting opportunity.
"Roginsky refused to engage in a sexual relationship with Ailes. As a result, Fox News and Ailes retaliated," the lawsuit said.
A lawyer for the former Fox News chief rejected the description of Roginsky's meetings with him as "total hogwash."
"Mr. Ailes vociferously denies her allegations," said a statement issued by the office of his counsel Susan Estrich.
"This copycat complaint is not about discrimination or retaliation. This is about someone who wants to pile on in a massive character assassination in order to achieve what she did not accomplish on the merits."
Roginsky's lawsuit also named Fox News co-president Bill Shine, claiming he refused Roginsky a permanent job at Fox, in part because she failed to side with Ailes in the harassment suit filed against him by on-air host Gretchen Carlson.
According to the suit, Shine retaliated against Roginsky "because of her complaints of harassment and... because (she) refused to malign Gretchen Carlson and join 'Team Roger' when Carlson sued Ailes for sexual harassment."
Roginsky seeks unspecified compensatory and punitive damages in the complaint against the cable channel, which did not immediately respond to an AFP query.
Ailes stepped down as chairman of Fox News and the Fox Business Network on July 21 last year in a chain of events touched off when Carlson filed a lawsuit accusing Ailes of firing her because she resisted his sexual advances.
Ailes denied the allegations but reportedly was forced to resign under pressure.
In September, Fox News settled the Carlson lawsuit for a reported $20 million, and apologized for her treatment on the job.
Separately, The New York Times reported this past weekend that Bill O'Reilly, a star Fox News commentator, has been accused of harassment by at least five women associated with the network.
It said the company and O'Reilly had paid the five women a total of $13 million in the cases that span 15 years.
O'Reilly did not deny the allegations, but said his prominence made him "vulnerable to lawsuits from individuals who want me to pay them to avoid negative publicity."