Martin Peretz has been editor-in-chief of The New Republic since 1974. Simultaneously he has kept up his teaching at Harvard University, where he has been a part-time lecturer in Social Studies since joining tnr. Peretz received his B.A. degree from Brandeis University and M.A. and Ph.D. from Harvard University.

Peretz holds the honorary degree of Doctor of Laws from Bard College (1982), Coe College (1983), Long Island University (1988), Brandeis University (1989), Hebrew College (1990), Chicago Theological Seminary (1994), and the degree of Doctor of Philosophy honoris causa from the Hebrew University of Jerusalem (1987). In 1982, he was awarded the Jerusalem Medal. He also holds the Medal of Distinction of the University of Missouri's School of Journalism and the National Magazine Award for Outstanding Achievement in Essays and Criticisms of the Columbia University Graduate School of Journalism.

Peretz is co-founder and was co-chairman of the Board of TheStreet.com, a publicly traded company on the NASDAQ, and he remains a Director. The NASDAQ has a 20% interest in The Marker, a financial e-mail publication of Ha'aretz. He is chairman of the Board of the Digital Learning Group, an e-publisher of college textbooks and also of Enews.com, a magazine subscription website. He has served for several decades as a director of 11 mutual funds in the Dreyfus-Mellon Group. Previously, he served on the Board of Directors of the Bank Leumi of New York and the Carmel Container Corporation. He was a co-founder of Leukosite, a biotechnology and pharmaceutical company, which, after it became a public company, was merged into Millennium Pharmaceuticals.