Jason Wolkow Epstein (born January 26, 1928) is an American editor and publisher.

Born in Cambridge, Massachusetts, Epstein attended public schools in Milton, Massachusetts. He graduated from Columbia College of Columbia University in 1949 and was elected to Phi Beta Kappa. He received a Master of Arts degree from Columbia the following year and joined Doubleday and Company as an editorial trainee.

At Doubleday, he saw the need for inexpensive, well made paperbacks of the kinds of books that his classmates, many of them veterans studying on the GI Bill, were reading but couldn't afford to own in their hardcover editions. With the support of Ken McCormick, Doubleday's chief editor, he launched Anchor Books, the first so-called Quality Paperbacks, which quickly became the dominant paperback format. In 1954 Anchor Books won the Carey-Thomas Award.

In 1958 he left Doubleday to join Random House where he served as editorial director until his retirement in 1999. At Random House he edited such writers as Jane Jacobs, Norman Mailer, Philip Roth, Gore Vidal, Vladimir Nabokov, E. L. Doctorow, Michael Korda and Peter Matthiessen. During the New York newspaper strike of 1963 Epstein, his brother Zach and their friends Robert Lowell and Elizabeth Hardwick created The New York Review of Books and turned to their friend Robert Silvers to be its editor along with Epstein's brother Zach.

In 1979 with the critic Edmund Wilson he conceived the Library of America, well-made, reliable editions of important American writers. With the support of the Ford Foundation and the National Endowment for the Humanities, the first volumes were published in 1982. He later published The Reader's Catalogue of 40,000 titles available by mail order, an analog precursor of online book selling. In 2004, he co-founded On Demand Books, marketer of the Espresso Book Machine, which reproduces a paperback book from a digital file in a few minutes. Epstein has predicted that the Espresso Book Machine will supplant the 500-year-old Gutenberg technology.