ISR may refer to:
Organizations Institute for Strategy and Reconciliation Institutional and Scientific Relations, of the European Commission International Star Registry, a company selling the right to name stars ISR International School on the Rhine, Germany
Publications ISR, a socialist magazine, 1900-1918 Information Systems Research International Socialist Review (disambiguation), U.S. publications International Statistical Review International Studies Review Israel Studies Review
Science and technology Biology In-stent restenosis, recurrence of stenosis after stenting Plant-induced systemic resistance, plant response to infection
Computers In-Service Register or Interrupt Service Register, in a PIC Interrupt service routine
Other science In-situ recovery, a mining technique Incoherent scatter radar, for studying the ionosphere Intersecting Storage Rings, a particle collider at CERN Injection site reaction, a reaction that occurs initially at the site of an injection or infusion
Other uses ISR, country code for Israel Indiana Southwestern Railway, US Inuvialuit Settlement Region, Northwest Territories, Canada Ipoh-KL Sentral Route, a train service, Malaysia ISR Racing, a team from Czech Republic Israir (designator ISR), an Israeli airline Italian Social Republic, 1943–1945 Joint Functional Component Command for Intelligence, Surveillance and Reconnaissance, of the US Strategic Command Intelligence, surveillance and reconnaissance, in military intelligence International Search Report, in international patent law