Dr Walsh told TODAY Extra she was invited to fly to NY to meet the host after she had appeared as a guest on the O'Reilly Factor from a Los Angeles studio. Those allegations led to the departure of another of Fox's primetime stars, Megyn Kelly, who also accused Ailes of inappropriate behavior.
Some analysts believe that James and Lachlan Murdoch - the sons of 21st Century Fox executive chairman Rupert Murdoch - made the call on O'Reilly to change the Ailesian culture at the network and to cement their control following his departure. Ailes has repeatedly denied any wrongdoing. (Ailes received a $40 million payout when he left).
"It is tremendously disheartening that we part ways due to completely unfounded claims", O'Reilly said. "But that is the unfortunate reality that many of us in the public eye must live with today".
O'Reilly's pugnacious personality wasn't just an onscreen affectation, with one of the settlements going to a woman who complained about being shouted at in the newsroom.
Earlier, with the disclosure of multiple settlements involving sexual harassment allegations against him, O'Reilly was forced out of his position as a prime-time host on Fox News. Eric Bolling, a regular presence on The Five, will take the 5 p.m. slot.
Starting Monday, Carlson's show will be followed at 7 p.m. MDT by "The Five", relocating from its afternoon slot.
Activist groups such as the National Organisation for Women have been bringing pressure to bear for weeks on the firm to fire O'Reilly in a case that NOW said became emblematic of the "culture of sexual harassment at Fox News" and requires an "immediate independent investigation". NY magazine said that Rupert Murdoch and his sons James and Lachlan, who run Fox parent 21st Century Fox, had decided that O'Reilly was out and executives were planning the exit.More news: How Trump insurance changes could affect coverage next year
"Getting rid of the old guard is a way to do that", said Dan Cassino, a professor at Fairleigh Dickinson University and the author of "Fox News & American Politics: How One Channel Shapes American Politics & Society".
News has not independently confirmed the story. "Personally, I think he shouldn't have settled".
More than 50 companies publicly announced they wouldn't advertise on The O'Reilly Factor following the publication of a New York Times report, which suggested the news man and Fox News paid millions to settle complaints from five women.
Fox News could have sustained the defections for a while as advertisers moved their spots into other programs.
(AP Photo/Mary Altaffer). A security guard looks out of the the News Corp. headquarters in Midtown Manhattan, Wednesday, April 19, 2017.
The risk for Fox News would have also intensified during the upfront advertising market, already in play, when companies decide where to make their advance commitments for commercial time that runs during the 2017-18 season.
O'Reilly is also one of the country's most popular nonfiction authors.