MSI may refer to:

Organizations Macedonian Scientific Institute, an institution in Sofia, Bulgaria Marketing Science Institute, a nonprofit learning institution in Cambridge, Massachusetts, US Media Sport Investment, the international fund of investors that ran Sport Club Corinthians Paulista Millennium Science Initiative, an international program bringing technology to developing nations Ministry of Science and Innovation (New Zealand) Minority-serving institution, in US higher education MSI Reproductive Choices, an international non-governmental organisation providing contraception and safe abortion services, with a global HQ in London, UK Museum of Science and Industry (Chicago), US Science and Industry Museum, in Manchester, England University of Minnesota Supercomputing Institute Italian Social Movement (Movimento Sociale Italiano), a defunct post-fascist party

Companies Micro-Star International, a Taiwanese information technology company Midwest Scientific Instruments, a defunct American computer company Morgan Stanley (Broker ID), an American financial services company Motorola Solutions (NYSE: MSI), an American data communications and telecommunications equipment provider Movie Star (company) (AMEX: MSI), an American clothing manufacturer

Science and technology MSI Barcode, a continuous numeric barcode symbology Microsatellite instability, an abnormality of DNA Mass spectrometry imaging, a technique used in mass spectrometry Mass sociogenic illness, the rapid spread of physical symptoms of illness among the members of a group with no physical or infectious cause Magnetic source imaging, magnetoencephalography combined with magnetic resonance imaging Multispectral imaging, the capture of multiple, specific wavelengths in the electromagnetic spectrum Musculoskeletal injury, damage of muscular or skeletal systems which is usually due to a strenuous activity

Computing .MSI, the filename extension of Windows Installer packages Medium scale integration, a generation of integrated circuit chips which contain hundreds of transistors Message Signaled Interrupts, a PCI 2.2 interrupt-mechanism MSI protocol, a basic cache-coherence protocol used in multiprocessor systems

Other uses Maison du Sport International, an office complex in Lausanne, Switzerland Maritime safety information, emergency signal communication Medical Service Insurance, the Government of Nova Scotia's health insurance Mid-Season Invitational, an annual League of Legends tournament Mindless Self Indulgence, an American rock band Multistakeholder initiative, a governance structure Inshore minesweeper (US Navy hull classification symbol: MSI), See List of mine warfare vessels of the United States Navy