Weisman holds both a bachelor's and master's degree in literature from Northwestern University. He is Laureate Associate Professor in Journalism and Latin American Studies at the University of Arizona, where he leads an annual field program in international field journalism. He has also taught writing and journalism at Prescott College and Williams College and has been a Fulbright Scholar in Colombia.

He has written several books and won numerous international awards for his work in journalism and literature, the most recent being the critically acclaimed The World Without Us, which describes a post-human scenario of the planet. Among his other works are Gaviotas: A Village to Reinvent the World (1998), winner of the Social Inventions Award from the Global Ideas Bank, An Echo In My Blood (1999), La Frontera: The United States Border With Mexico, and We, Immortals (1979). His reports on Latin America have appeared in Harper's, The New York Times Magazine, the Los Angeles Times magazine, the Atlantic Monthly, Orion, Audubon, Mother Jones, Discover, Condé Nast Traveler, Resurgence, and several anthologies, including The Best American Science Writing 2006.

Weisman is also an editor of radio documentaries for Homelands Productions, creating reports for National Public Radio.

Among his awards and citations are the Four Corners Award for Best Nonfiction Book, a Los Angeles Press Club Award for Best Feature Story, a Best of the West Award in Journalism, a Robert F. Kennedy Journalism Citation, the Unity Media Award, the Brazilian government's Premio Nacional de Jornalismo Radiofonico, and major grants from The Ford Foundation, the Corporation for Public Broadcasting, the Rockefeller Foundation and the MacArthur Foundation.

Weisman appeared as a guest on The Daily Show on August 21, 2007.

He lives with his wife, bronze sculptor Beckie Kravetz, in western Massachusetts.