The Mississippi Defense Initiative (MDI) is a program from the United States Department of Defense Office of Economic Adjustment, The University of Southern Mississippi, and public and private sector partners that believe in the promise of a diverse Mississippi economy.

The MDI unites federal labs, defense companies, other private businesses, Mississippi entrepreneurs, Mississippi educational institutions, Mississippi public entities, and domain experts to design, develop, and roll-out strategies to transition from heavy defense-oriented revenue models to commercial revenue models.