HMI may refer to:

• Hahn-Meitner-Institut, now Helmholtz-Zentrum Berlin, a German research institute
• Hanson Musical Instruments, a manufacturer of electric guitars
• Hartz Mountain Industries, an American holding company
• HD Mining International, a mining company in Vancouver, British Columbia, Canada
• Hetrick-Martin Institute, an LGBT youth organization in New York City
• High Mountain Institute, in Leadville, Colorado, United States
• Himalayan Mountaineering Institute, in Darjeeling, India
• HMI Hotel Group, a hotel management company in Japan
• Holistic Management International, an American non-profit organization
• HornAfrik Media Inc, a media organization based in Mogadishu, Somalia
• Hotel Meliá, in Ponce, Puerto Rico
• Houston Mechatronics, Inc, see Houston Mechatronics, Inc
• Hualien Media International, a global entertainment company in Taipei, Taiwan
• Muslim Students' Association (Indonesia)

• Helioseismic and Magnetic Imager, on the Solar Dynamics Observatory spacecraft
• hexamethyleneimine, an organic compound
• Human–machine interaction
• Human–machine interface
• Hydrargyrum medium-arc iodide lamp, used for stage lighting

• Hami Airport, in Xinjiang, China
• Hammond–Whiting (Amtrak station), in Indiana
• Her Majesty's Inspectorate of Education, in Scotland
• Northern Huishui Miao language, spoken in China