CIR

CIR may refer to:

• Caledonian Road & Barnsbury railway station, the standard code for this railway station
• Carbon Isotope Ratio analysis, a subset of isotope ratio mass spectrometry
• Carrier-to-interference ratio or Signal:Interference ratio, a term used in radio transmission
• Center for Individual Rights, an individual rights protection group
• Center for Investigative Reporting, a nonprofit investigative journalism organization
• Central Ischaemic Response, a cause of fainting, see Syncope (medicine)#Causes
• Christian Initiative Romero, a German non-profit organisation supporting industrial law and human rights in Central America
• Christmas Island Resort, a holiday resort on Christmas Island, an Australian territory in the north-eastern Indian Ocean
• Color Infrared, a photographic technique used, for example, in aerial photography
• Combustion Integrated Rack, an International Space Station microgravity research tool
• Command Instrument Rating, a category of aircraft pilot Instrument Rating
• Commissioner of Internal Revenue, a US Treasury position
• Committed Information Rate, a synonym for minimum guaranteed bitrate in telecommunications
• Committee on International Relations (University of Chicago), a graduate program
• Committee on International Relations, the name of the United States House Committee on Foreign Affairs prior to 2007
• CIR Group, Compagnie Industriali Riunite an industrial holding company of the De Benedetti Group
• Component Infrastructure Roadmap, a computer systems service-oriented architecture
• Comprehensive Immigration Reform Act of 2006, a US Senate Bill on border security
• Comprehensive Immigration Reform Act of 2007, full name: Secure Borders, Economic Opportunity and Immigration Reform Act, a US Senate Bill
• Consumer IR, infrared remote control and communication
• Coordinator for International Relations, a position within the JET Program
• Corotating Interaction Region, the interface between fast and slow regions of the solar wind
• Cosmetic Ingredient Review, a consumer safety group
• Cost:Income Ratio, one of a series of financial ratios
• Cox–Ingersoll–Ross model for interest rate dynamics
• Circinus (constellation), written Cir, a standard astronomical abbreviation
• Channel 1 Releasing, an adult film studio
• The Campionato Italiano Rally the official title of the Italian Rally Championship.