Martin H. Peretz (born December 6, 1938) is an American billionaire, academic, Harvard professor emeritus, media figure, and political activist renowned for his influential role in journalism and publishing. He is known for his neoconservative to liberal views on Israel and U.S. politics, specifically his liberal Zionist outlook, with his Jewish heritage and strong advocacy for Israel being central to his worldview. Peretz was the longtime publisher, former owner, and editor-in-chief (1974–2012) of The New Republic, which he acquired in 1974 and transformed into a platform for his ideological blend of liberalism and hawkish foreign policy stances, and he maintained a long-term professional relationship with Wieseltier. In 1996, he co-founded TheStreet.com with Jim Cramer, expanding his influence into digital media and finance. He sold The New Republic in 2016 amid controversies over the magazine's direction and his personal views, including allegations of antisemitic undertones in his social media activity. Beyond media, Peretz has taught at Harvard, lecturing on social theory and politics, and has been active in venture capital, philanthropy (particularly Jewish causes), political networks, and Democratic politics.