Isidor Feinstein Stone (December 24, 1907 – June 18, ****), born Isidor Feinstein, better known as I. F. Stone and Izzy Stone, was an American investigative journalist and author.

He is best remembered for his self-published newsletter, I. F. Stone's Weekly. In 1999, a New York University poll of journalists ranked I.F. Stone’s Weekly at 16 in "The Top 100 Works of Journalism in the United States in the 20th Century," placing the Weekly second among print journalism.