Last Saturday, the New York Times reported that O'Reilly personally reached a $32 million settlement in January with former Fox News legal analyst Lis Wiehl. The following month, Fox News entered into a multiyear contract renewal with O'Reilly, bumping up his salary to $25 million a year from around $20 million under his previous deal.

"It was news to me when we saw that number the other day," he said, speaking at the Paley Center for Media International Council Summit in New York on Wednesday, referring to the $32 million figure. That settlement was not entered into by 21st Century Fox, he noted.

"It's easy to look from the outside and say, 'Didn't you know that?'" he said. "I think the issue becomes, how do you react to those things" once they are brought to light.

Murdoch said that the media conglomerate fired O'Reilly after investigating the complaints, as well as Fox News founder Roger Ailes following other sexual-harassment allegations. "You investigate things thoroughly, you make what you think is the best decision," he said, when asked about O'Reilly by CNBC's Julia Boorstin, who interviewed the exec at the Paley Center event.