ISM or Ism may refer to:

• Incredible Shrinking Man, a film
• ISM (album), a 2012 album by Norwegian electronic music producer Savant
• Ism (film), a 2016 Indian Telugu-language action film starring Nandamuri Kalyan Ram
• Ism (band), an East Coast-based alternative rock quartet

• Institute for Supply Management, with headquarters in Arizona
• International Sports Management, English sports management company
• International Spy Museum, Washington, D.C.
• Independent Society of Musicians, (formerly Incorporated Society of Musicians) United Kingdom professional body
• Independent Sacramental Movement, section of Christianity
• International Society for Micropiles, concerned with micropile building techniques
• ISM Canada, an information technology service company based in Regina, Saskatchewan
• ISM Racing, a former autoracing team owned by Bob Hancher

• International Socialist Movement, Scotland
• International Solidarity Movement, organization focused on assisting the Palestinian cause in the Israeli-Palestinian conflict
• Italian Social Movement, a former neo-fascist and post-fascist political party in Italy

• Indian School of Mines, a Deemed University under the Section 3 of University Grants Commission Act, 1956
• Indian School, Muscat, a Central Board of Secondary Education-affiliated school in Oman
• International School of Management (Paris), an American graduate institution based in Paris and New York City
• ISM University of Management and Economics, an institution of management education based in Lithuania
• International School Moshi, Tanzania
• Illinois State Museum
• The International School of Minnesota, a private preparatory school
• Independence Seaport Museum, a maritime museum located in Philadelphia

• ISM band, the industrial, scientific and medical radio bands
• Idiopathic sclerosing mesenteritis, disease of the small intestine
• Interstellar medium, in astronomy
• Implicit Shape Model, technique in computer vision
• InterSystems MUMPS, medical computer system
• .ism, a filename extension for InstallShield MSI projects

• Ism (name), the Arabic word for a personal name
• -ism, a suffix appended to many philosophical concepts
• Industry Structure Model, a formal model for skills and training, now superseded by SFIAPlus
• International Safety Management Code, used in shipping
• Kissimmee Gateway Airport (IATA airport code)
• Ian Standish Monteith Hamilton (1853–1947), British general
• Imperial Service Medal, decoration affiliated with the British Imperial Service Order
• Internationale Süßwarenmesse, confectionery fair held annually at Cologne trade fair
• International student ministry

• ISMS (disambiguation)
• Inner Sydney Montessori School, Australia