Michèle Angélique Flournoy is an American defense policy advisor and former government official. She was Deputy Assistant Secretary of Defense for Strategy under President Bill Clinton and Under Secretary of Defense for Policy under President Barack Obama.

The United States under secretary of defense for policy (USDP) is a high level civilian official in the United States Department of Defense. The under secretary of defense for policy is the principal staff assistant and adviser to both the secretary of defense and the deputy secretary of defense for all matters concerning the formation of national security and defense policy.