ISF

ISF may stand for:

Science and technology

• Interstitial fluid
• Imaging Science Foundation
• Incremental sheet forming
• Information Security Forum, an international information security best practices organization
• Ingenieurs Sans Frontieres (Engineers Without Borders)
• Ink Serialized Format, a vector image file format from Microsoft

Education

• Idries Shah Foundation, educational charity
• Independent Schools Foundation Academy(ISF), private international school in Hong Kong
• Insaf Student Federation (ISF), it is the largest Center-Left Student organization in the Nation and the official student wing of the Pakistan Tehreek-e-Insaf political party
• Institut für Schweißtechnik und Fügetechnik der RWTH Aachen (Joining and Welding Institute of the RWTH Aachen) in Aachen, Germany
• International School of Florence
• International School Sport Federation, sports governing body for high school sport
• Internationale Schule Frankfurt Rhein-Main

Sport

• International Snowboard Federation
• International Softball Federation
• International Skyrunning Federation, world sports governing body for skyrunning

Business

• Importer Security Filing
• Impôt de Solidarité sur la Fortune, a French wealth tax

Arts

• Idaho Shakespeare Festival, theater company

Other

• Île Sans Fil, a community wireless network based in Montreal, Canada
• Internal Security Forces, of Lebanon
• Iraqi security forces
• Lexus IS F
• Italian Strategic Fund