MI-9, MI9, MI 9 may refer to:

• MI9, British Military Intelligence Section 9
• Mi9, an Australian digital media company, fully owned subsidiary of Nine Entertainment Co.
• Mil Mi-9, a variant of the Mil Mi-8 helicopter
• Michigan's 9th congressional district
• M-9 (Michigan highway)

MI9, the British Directorate of Military Intelligence Section 9, was a department of the War Office between 1939 and 1945. During World War II it was tasked with facilitating escapes of British prisoners of war and facilitating the return of those who succeeded in evading capture in enemy occupied territory (for example, aircrew who had been shot down and soldiers stranded after the Battle of Dunkirk). It also communicated with British prisoners of war and sent them advice and equipment.