John Alfred Hannah (October 9, 1902 – February 23, 1991) was president of Michigan State College (later Michigan State University) for 28 years (1941-1969), making him the longest serving of MSU's presidents.
He is credited with transforming the school from a regional undergraduate college into a large national research institution.
After his resignation from the university, Hannah became head of the United States Agency for International Development (USAID).