Ms Weiss, who started her career working at Jewish news outlets, is known for her support of Israel and her criticism of “cancel culture”.
Since its start as a newsletter in 2021, The Free Press has attracted 1.5 million subscribers, including more than 170,000 paid subscribers.
It has drawn attention for reports such as a piece critical of NPR by one of its former business editors, Uri Berliner, as well as an investigation of some photos used by mainstream news outlets to illustrate famine in Gaza, which said many of those featured suffered other health conditions.
Big name contributors include historian Niall Ferguson and economist Tyler Cowen.
Mr Ellison said the appointment of Ms Weiss as editor-in-chief was part of a bigger effort to modernise content at Paramount and make CBS the “most-trusted name in news”.
“We believe the majority of the country longs for news that is balanced and fact-based, and we want CBS to be their home,” he said.
