Bari Weiss was born on March 25, 1984, in Pittsburgh, Pennsylvania, to Lou and Amy Weiss, owners of a Pittsburgh flooring and home furnishings company. She grew up within a closely-knit Jewish community in Squirrel Hill. She later attended Columbia University, where she was a prominent student journalist and activist.

Weiss began her professional journalism career as an op-ed and book review editor at The Wall Street Journal. She then joined The New York Times as an op-ed staff editor and writer covering culture and politics. In 2020, she left The New York Times and, shortly after, launched a newsletter called Common Sense on Substack. The newsletter later expanded into The Free Press, a media company she co-founded with her wife, journalist Nellie Bowles.

The Free Press grew to 1.5 million subscribers and generated an estimated $15 million annually before Paramount Skydance acquired it for approximately $150 million in 2025. As part of the deal, Weiss was named Editor-in-Chief of CBS News. As part of her programming overhaul, she created Things That Matter, a town hall debate series, for which she served as the host of the inaugural special.