Ms. Kelly had also invited Juliet Huddy, another former Fox employee who reached a settlement agreement after accusing Mr. O’Reilly of sexual harassment, to be a guest on the show Monday.
In her remarks, Ms. Kelly also described an email she sent to top Fox executives last November.
At the time, Ms. Kelly had published a book in which she outlined sexual harassment claims concerning Roger E. Ailes, the former Fox News chief executive. Mr. Ailes was let go from the network after an investigation into several other claims; he died this year.
The day that Ms. Kelly’s book came out, Mr. O’Reilly appeared on “CBS This Morning” to promote his latest book. Asked on the show to comment on Ms. Kelly’s allegations, he said he was “not interested.”
“I am not interested in basically litigating something that is finished that makes my network look bad,” Mr. O’Reilly said.
As The Times has previously reported, Ms. Kelly sent an email about Mr. O’Reilly to top Fox executives that day. On Monday, she shared part of that email with her audience.
“Perhaps he didn’t realize the kind of message his criticism sends to young women across the country about how men continue to view the issue of speaking out about sexual harassment,” she wrote. “Perhaps it’s his own history of harassment of women which has, as you both knew, resulted in payouts to more than one woman, including recently, that blinded him to the folly of saying anything other than ‘I am sorry for the women of this company who never should have gone through that.’”
Ms. Kelly, who worked at Fox News from 2004 until January of this year, also criticized Irena Briganti, the network’s top communications executive, for “vindictiveness.”
Ms. Briganti did not immediately respond to a request for comment. A spokesman for 21st Century Fox, the parent company of Fox News, said, “Irena is a valued colleague and she has our full support.”
Ms. Kelly is a month into her role as host of “Megyn Kelly Today.” The show’s ratings have gotten off to a rough start: For the week of Oct. 9, she had about 2.3 million viewers, a 23 percent drop from the figure for the same time slot a year ago.
On Thursday, in an attempt to increase the show’s fun factor, Ms. Kelly danced to a Pitbull song with Hoda Kotb, the co-host of the 10 a.m. hour of “Today.” The two women asked audience members to join them in an “Ellen”-style shindig, with limited success. A clip of the brief dance party went viral on social media.
But amid the cascade of sexual harassment allegations against the film mogul Harvey Weinstein, Ms. Kelly has also returned to her old specialty as a news analyst and stirrer of the cultural pot. She has talked increasingly about sexual harassment, including condemning the fashion designer Donna Karan for defending Mr. Weinstein.
Ms. Huddy appeared with her lawyer, Douglas Wigdor, on Ms. Kelly’s show. Because of the confidential terms of her settlement, Ms. Huddy said she could not talk about her specific allegations against Mr. O’Reilly.
When she was introduced moments after Ms. Kelly’s excoriation of her former network, Ms. Huddy said, “I’m trying to keep it together, I’m getting so emotional. That was amazing, by the way.”