CIR or Cir may refer to:

• Christmas Island Resort, a casino/resort in the northeastern Indian Oceans
• CIR, FAA/IATA code for Cairo Regional Airport
• CIR, station code for the Caledonian Road & Barnsbury railway station in the UK

• Center for Individual Rights, a US non-profit public interest law firm
• Center for Investigative Reporting, a nonprofit journalism organization
• Christian Initiative Romero, a German non-profit organization supporting industrial law and human rights in Central America
• Cosmetic Ingredient Review, a consumer safety group

• Commission Internationale de Ravitaillement, an inter-governmental body for coordinating purchases among Allies in World War I
• Commissioner of Internal Revenue, a US Treasury position
• Committee on International Relations, renamed the United States House Committee on Foreign Affairs in 2007
• Comprehensive Immigration Reform Act of 2006, a US Senate bill
• Convention of Republican Institutions, a defunct French political party
• Cyber and Information Domain Service, the cyber branch of Germany's military (German: Cyber- und Informationsraum)

• Carbon isotope ratio analysis, a subset of isotope ratio mass spectrometry
• Central ischaemic response, a cause of fainting
• Cir, abbreviation for the constellation Circinus
• CIR (gene), a gene that encodes the protein corepressor interacting with RBPJ in humans
• Corotating interaction region, the interface between fast and slow regions of the solar wind

• Carrier-to-interference ratio, in radio transmission
• Color infrared film, in photography
• Combustion Integrated Rack, an International Space Station microgravity research tool
• Committed information rate, or minimum guaranteed bitrate, in telecommunications
• Consumer IR, a class of remote control and communication devices

• Campionato Italiano Rally (Italian Rally Championship), in automobile racing
• CIR, ICAO code for Arctic Circle Air, ICAO code
• CIR Group, an Italian holding company
• Committee on International Relations (University of Chicago), a graduate program
• Coordinator for International Relations, a position within the Japan Exchange and Teaching Program
• Cox–Ingersoll–Ross model, a model for interest rate dynamics

This disambiguation page lists articles associated with the title CIR.
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