C1, C01, C.I or C-1 may refer to:
Arts and media C1, a note-octave in music C1 Television, a Mongolian television channel Cinema One, Philippine pay TV channel Schecter C-1 Hellraiser FR, a guitar model A Yamaha grand piano model "C1", a slang expression in the video game Counter-Strike, used to express agreement
Biology and medicine Anatomy Cervical vertebra 1, the first cervical vertebrae of the vertebral column Cervical spinal nerve 1, a spinal nerve of the cervical segment
Biochemistry C1 complex, the first component of the classical complement pathway C1 domain, an important secondary messenger protein domain C1-inhibitor, a human serine protease inhibitor C1 regulatory sequence for the insulin gene Apolipoprotein C1, a human lipoprotein Chlorophyll c1, a form of chlorophyll Cytochrome C1, a precursor protein to Cytochrome C Proanthocyanidin C1, a type of polyphenolic compound Prostaglandin C1, a form of prostaglandins
Other uses in biology and medicine C1 and P1 (neuroscience), a component of the visual evoked potential ATC code C01, a subgroup of the Anatomical Therapeutic Chemical Classification System "malignant neoplasm of base of tongue", a form of oral cancer (ICD-10 code "C01") A microfluidic single-cell analysis system sold by Fluidigm, short name C1
Chemistry C1 Chemistry, study of methane, methanol, carbon monoxide, carbon dioxide
Computing Hardware C-One, a single-board microcomputer C1 Famicom TV, a family of Famicom television-set hybrids manufactured by Sharp Corporation in 1983 ATI C1, codename of the Xbox 360 GPU Xenos Apple C1, a cellular modem chip A type of error on a compact disc (CD); see Compact disc § Integrity LG C1, a television set released in 2021
Other uses in computing C0 and C1 control codes defined in ISO 6429 C1 (protocol), a 1984 protocol for file transfer, also known as "Punter" TCSEC C1 security class A CPU power state in the Advanced Configuration and Power Interface
Mathematics , the set of all continuously differentiable functions C1 field, a quasi-algebraically closed field C1, the first of four pure modules taken in the Advanced Level (UK) Maths syllabus
Transportation Air C-1 Trader, a cargo-version of the S-2 Tracker anti-submarine warfare aircraft of the US Navy AEG C.I, a German World War I reconnaissance aircraft AGO C.I, a 1915 German reconnaissance biplane Albatros C.I, a 1915 German two-seat general-purpose biplane Aviatik C.I, a 1915 German observation plane Cierva C.1, a 1920 Spanish experimental autogyro DFW C.I, a WWI German reconnaissance aircraft Douglas C-1, a cargo/transport airplane produced by Douglas Aircraft for the U.S. Army Air Service starting in 1925 Fokker C.I, a 1918 German reconnaissance biplane Friedrichshafen C.I, a 1914 German single-engined amphibious reconnaissance biplane Hansa-Brandenburg C.I, a 1916 German 2-seater armed single-engine reconnaissance biplane Kawasaki C-1, an indigenous transport aircraft of the Japanese Air Self-Defense Forces Loring C-1, an interwar period Spanish fighter prototype Otto C.I, a 1915 German reconnaissance biplane Rumpler C.I, a 1915 German two-seater single-engine reconnaissance biplane Southern Cross Airport (New Jersey) (FAA LID: C01)
Land Routes Circumferential Road 1 or C-1, an arterial road of Manila, Philippines London Buses route C1 Route C1 (Shuto Expressway), the Inner Loop of Tokyo's Shuto Expressway system Claro M. Recto Avenue, a road in Metro Manila, Philippines Massachusetts State Route C1 Câble 1, a cable car route in Grand Paris, France
Land vehicles BMW C1, a cabin scooter Chevrolet Corvette C1, first generation sold from 1953 to 1962, denoted a solid-axle rear-end Citroën C1, a small car Ford C1 platform, the Ford Motor Company's global compact car automobile platform Leapmotor C01, a battery electric executive sedan Lit C-1, a prototype cabin motorcycle Nimrod NRA/C1, a 1981 test design racing car Sauber C1, a Sauber sport car
Other uses in land transport C-1, the numberplate of the Prime Minister of Australia's official VIP transportation A type of heavy goods vehicle licence A one-way traffic sign in the Vienna Convention on Road Signs and Signals
Rail C1-class Melbourne tram Bavarian C I, an 1847 German steam locomotives class Ceylon Government Railway C1, a steam locomotive class GNR Class C1 (small boiler), a British 4-4-2 steam locomotive class (classified C2 during LNER ownership) GNR Class C1 (large boiler), a British 4-4-2 steam locomotive class LB&SCR C1 class, an 1882 British freight steam locomotive Long Island Rail Road C1, a bilevel railcar built by Tokyu Car Corporation NER Class C1, a British 0-6-0 steam locomotive class PRR C1, an American PRR steam locomotive Finnish Steam Locomotive Class C1
Sea C-1, later renamed , a Spanish Navy submarine , a C-class submarine of the Royal Navy , a C-class submarine of the US Navy , a protected cruiser of the US Navy Type C1 ship, a small cargo vessel built by the US in large numbers before and during World War II
Space Cluster 1, also known as Rumba, an ESA satellite
Sports
C1, a solo canoe discipline including sprint canoe and canoe slalom C1 (classification), a para-cycling classification Class One offshore powerboat racing, abbreviated "C1" 'C1', the top category in Group C sportscar racing, used between 1985 and 1990 C1, the UEFA Champions League (formerly known as the European Cup) in football Serie C1, the third highest football league in Italy until 2008
Other uses C1, an international standard paper size defined in ISO 216 (648×917 mm) Bills C-1 and S-1, a pro forma bill normally introduced at the start of a parliamentary session in the Canadian House of Commons C1, also known as Vlakplaas, a unit of the South African Police responsible for assassinating opponents of Apartheid during the 1980s C1, a level in the Common European Framework of Reference for Languages C1, the use class for hotels, in town and country planning in the United Kingdom C1, a NRS social grade in the UK for the lower middle class A 2001 1.3 megapixels Olympus digital camera model A class of FM radio broadcasting in North America C1 pylon, a type of high voltage pylon Caldwell 1 (NGC 188), an open cluster in Cepheus C-1 visa, a type of visa for individuals transiting through the US C1 Espresso, café in Christchurch, New Zealand Capital One, an American banking company Alpha Centauri Ab, formerly called Candidate 1
See also CL (disambiguation) CI (disambiguation) 1C (disambiguation)