Marshall Ganz (born March 14, 1943) is the Rita E. Hauser Senior Lecturer in Leadership, Organizing, and Civil Society at the Kennedy School of Government at Harvard University.

He is credited with devising the successful grassroots organizing model and training for Barack Obama's winning 2008 presidential campaign.

For three years after World War II, his family lived in occupied Germany, where his father served as a US Army chaplain working with displaced persons.

[10] Ganz's experience with the farm workers led him to formulate his concept of "strategic capacity.," He says this explains how Chavez's farmworker organizing succeeded, while earlier efforts by radicals, and contemporaneous campaigns by the Agricultural Workers Organizing Committee (AWOC) sponsored by the AFL-CIO, and by the Teamsters, failed.

"[11] Strategic capacity, for Ganz, consists of three elements: motivation, access to relevant knowledge, and deliberations that lead to new learning.

Chavez's efforts eventually prevailed because his organizing team had stronger motivation, deeper knowledge of the Mexican-American culture of the Central Valley, and diverse perspectives that generated fresh tactical ideas.

Chavez worked with Chuck Detrick, founder of the Synanon drug treatment cult, to transform the internal life of the union.

Over the next three years, members of the Executive Board opposed to the direction Chavez was taking the union resigned, including Ganz in 1981.

Since completing his doctorate in 2000, he has been a lecturer in public policy, teaching courses on organizing, leadership, civic engagement, and community action research.

He has collaborated with Harvard professors Theda Skocpol on African-American fraternal organizations, and with Lani Guinier for a course on law and social movements.

Ganz teamed up with Harvard psychology professor Ruth Wageman in an effort to improve the volunteer programs of local chapters.

In June 2024, the investigator found “sufficient evidence” that Ganz had discriminated against the students on the basis of their ethnic identity — a finding that Elmendorf accepted as final.