The news has sparked more than 30 companies to cancel their ads on the show.
O'Reilly hasn't admitted any wrongdoing and said he settled for the sake of his family.
The book, debuting amid several sexual harassment allegations against O'Reilly that resurfaced in a New York Times expose, is presented as a defense of old-school values versus the "snowflakes" who are on "cable TV whining about social injustice and income inequality", according to O'Reilly.
The chaotic scene and rotating cast of characters may explain why Trump made a decision to go "off script" from remarks or talking points about domestic policy to defending O'Reilly, "a good person", in Trump's estimation, who it was recently reported paid out millions (along with Fox News) to settle sexual harassment claims and has since lost dozens of advertisers. The alleged payouts have prompted at least 38 advertisers to pull spots from "The O'Reilly Factor".
During election season, Donald Trump routinely veered off course while speaking, launching into tangents about one subject or another.
No more children for Kim Kardashian; she and Kanye consider surrogacy
She later confessed: "I can't carry anymore kids ... it's the worst.It's not going to be happy for me". Kim Kardashian has apparently accepted that her third child must be carried by a surrogate.
"This really is a sexual harassment enterprise", Waters said. Both Alies and O'Reilly have fought back against the allegations. O'Reilly, in a statement posted on his website on Saturday, said he had been unfairly targeted because of his prominence.
"They have treated women very badly", Waters said, referring to Fox News.
The number of companies pulling ads from O'Reilly's show continues to grow.
"Given the importance of women in every aspect of our business, we don't feel this is a good environment in which to advertise our products right now", she said. Last week, O'Reilly's traffic ranged from just 2.3 million viewers on Friday night to 3.5 million on Wednesday.
21st Century Fox referred PEOPLE to Fox News, which did respond to a request for comment.