Marshall Ganz is the Rita E. Hauser Senior Lecturer in Leadership, Organization, and Civil Society at the Harvard Kennedy School. He teaches, researches, and writes about leadership, narrative, strategy, and organization in social movements, civic associations, and politics. He grew up in Bakersfield, California, where his father was a rabbi and his mother a teacher. He entered Harvard University in the fall of 1960 but left a year before graduating to volunteer with the 1964 Mississippi Summer Project.

There he found his calling as an organizer for the Student Nonviolent Coordinating Committee, and in the fall of 1965 he joined César Chávez in his effort to unionize California farmworkers. During his 16 years with the United Farm Workers union, he gained experience in union, political, and community organizing; he rose to become Director of Organizing and was elected to the national executive council, where he served for eight years.

During the 1980s, he worked with grassroots groups to develop new organizing programs and designed innovative voter mobilization strategies for local, state, and national election campaigns. He has published in the American Journal of Sociology, American Political Science Review, American Prospect, Washington Post, Los Angeles Times, and Stanford Social Innovation Review, among others. His book, Why David Sometimes Wins: Leadership, Organization and Strategy in the California Farm Worker Movement, was published in 2009 and received the Michael J. Harrington Award from the American Political Science Association. In 2007–2008, he was instrumental in designing the grassroots organizing for Barack Obama's presidential campaign. In 2010, he received an honorary doctorate in theology from the Episcopal Divinity School.

In collaboration with the global Leading Change Network, comprised of organizers, researchers, and educators, she offers training, consulting, and support to social, civic, educational, health, and political groups worldwide on organizing, training, and leadership development. In 2024, Oxford University Press published her most recent book: People, Power, Change: Organizing for Democratic Renewal.