Susan Jacoby (1945-) is an American atheist, secularist, and author, most recently of the NY Times best seller, The Age of American Unreason, which is about anti-intellectualism.

Her book Freethinkers: A History of American Secularism was named a notable book of 2004 by The Washington Post and The New York Times. It was also named an Outstanding International Book of the Year by the Times Literary Supplement (London) and The Guardian.

Wild Justice: The Evolution of Revenge (1984) was a finalist for the Pulitzer Prize.

Jacoby, who began her career as a reporter for The Washington Post, has been a contributor to a wide variety of national publications, including The New York Times, the Los Angeles Times, The American Prospect, Mother Jones, The Nation, Glamour, and the AARP Bulletin and AARP Magazine. She is currently a panelist for "On Faith," a Washington Post-Newsweek blog on religion.

Jacoby graduated from Michigan State University in 1965. She lives in New York City and is director of the New York branch of the Center for Inquiry.