CID

CID may refer to:

Police units

Crime Investigation Department (India), intelligence wing of the Indian State Police
Criminal Investigation Department (Singapore), intelligence wing of the Singapore Police Force
Criminal Investigative Department, intelligence wing of the Ghanaian State Police
Criminal Investigation Department, a branch of many police forces
United States Army Criminal Investigation Command, of which the operations division is commonly abbreviated to CID

Caller ID, a telephone service that transmits the caller's telephone number to the called party
Card Identification Number, a security feature on credit cards
Cell ID, used to identify cell phone towers
Certified Interconnect Designer, a certification for printed circuit-board designers
Channel-iron deposits, one of the major sources of saleable iron ore
CID fonts, a font file format
Clinical Infectious Diseases, a medical journal
Collision-induced dissociation, a mass spectrometry mechanism
Combat Identification, accurate characterization of detected objects for military action
Compound identification number, a field in the PubChem database
Configuration interaction doubles, a variational quantum-chemical method for calculating partly correlated ground states
Content-ID, a URI scheme that allows the use of MIME within email
Controlled Impact Demonstration, a project to improve aircraft crash survivability
Cubic inch displacement, a measurement in internal combustion engines
University of Colombo, Centre for Instrument Development, in Sri Lanka

CID, the IATA code for The Eastern Iowa Airport in Cedar Rapids
Center for International Development, at Harvard University
Central Institute for the Deaf
Centro Insular de Deportes, an arena in Gran Canaria, Spain
Committee of Imperial Defence, a former part of the government of Great Britain and the British Empire
Community improvement district
Conseil International de la Danse, an umbrella organization for all forms of dance in the world
Council of Industrial Design, a UK body later renamed the Design Council