C3, C-3, C.3, C03, C.III or C-III may refer to:

Life and biology

* C₃ carbon fixation in plants * C3-convertase, an enzyme * Complement component 3, a protein of the innate immune system *

Apolipoprotein C3 Apolipoprotein C-III also known as apo-CIII, and apolipoprotein C3, is a protein that in humans is encoded by the ''APOC3'' gene. Apo-CIII is secreted by the liver as well as the small intestine, and is found on triglyceride-rich lipoproteins such ...

, a human very low density lipoprotein * ATC code C03 ''Diuretics'', a subgroup of the Anatomical Therapeutic Chemical Classification System *

Castavinol C3 Castavinol C3 is a castavinol, a natural phenolic compound found in red wines.Castavinol, a new series of polyphenols from Bordeaux red wines. Chantal Castagnino and Joseph Vercauteren, Tetrahedron Letters, Volume 37, Issue 43, 21 October 1996, p ...

, a natural phenolic compound found in red wines *

Cytochrome-c3 hydrogenase In enzymology, a cytochrome-c3 hydrogenase () is an enzyme that catalysis, catalyzes the chemical reaction :2 H2 + ferricytochrome c3 \rightleftharpoons 4 H+ + ferrocytochrome c3 Thus, the two substrate (biochemistry), substrates of this enzyme ...

, an enzyme * Haplogroup C-M217, called C3 in older publications * In human anatomy, C3 may refer to: ** Cervical vertebra 3, one of the cervical vertebrae of the vertebral column ** Cervical spinal nerve 3 * Clinical Cell Culture, a medical technology company * C03, Malignant neoplasm of gum ICD-10 code *

C3 Collaborating for Health C3 Collaborating for Health is a global, not-for-profit non-governmental organisation, based in London, that exists to find solutions to fight the epidemic of non-communicable diseases (NCDs). The C3 approach C3’s focus is on the main risk fac ...

, a health-promotion NGO * C3: an EEG electrode site according to the 10-20 system

Military

* C³, Command, control, and communications, a military concept * C-3 (plastic explosive), a plastic explosive related to C4 * C-3, a United States military designation for the

Ford Trimotor The Ford Trimotor (also called the "Tri-Motor", and nicknamed the "Tin Goose") is an American three-engined transport aircraft. Production started in 1925 by the companies of Henry Ford and ended on June 7, 1933, after 199 had been made. It w ...

* the designation for several German World War I and World War II armed reconnaissance aircraft ** AEG C.III **

AGO C.III The AGO C.III was a German reconnaissance biplane of World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Rus ...

, a reconnaissance biplane of World War I ** Albatros C.III **

DFW C.III __NOTOC__ The DFW C.III was a German reconnaissance aircraft produced during World War I. Powered by a Benz Bz.III The Benz Bz.III was a six-cylinder, water-cooled, inline engine developed in Germany for use in aircraft in 1914. Developing ...

, a DFW aircraft * NAG C.III, an engine powering the Gotha G.IV aircraft * C-3, a U.S. military transport version of the Martin 4-0-4 * Type C3 submarine (disambiguation), a World War II Imperial Japanese Navy cargo carrier submarine * Spanish submarine ''C-3'' * HMS ''C3'', a 1906 British C class submarine * Type C3-class ship, a type of merchant cargo ships of United States Maritime Commission "C" design * USS ''C-3'' (SS-14), a 1909 United States C class submarine * USS ''Baltimore'' (C-3), an 1888 protected cruiser of the United States Navy * Garda Crime and Security Branch (CSB), domestic security agency of Ireland's national police, also known as "C3" * C3 Howitzer, a lengthened variant of the M101 used by the Canadian Armed Forces

Technology

* C₃, characteristic energy, in astrodynamics, a measure of the rocket energy for an interplanetary mission that requires attaining an orbital velocity above escape velocity * C₃, the chemical symbol for ** Tricarbon ** Cyclopropatriene * C3.ai, an AI company founded by Thomas Siebel * C3 linearization, a computer science algorithm for resolving the order of method resolution in multiple inheritance conditions * Delfi-C3, a Dutch CubeSat satellite * Saturn C-3, a 1960 rocket in the Saturn C series * Chaos Communication Congress, the biggest annual hacker event in Europe * Chrysler Comprehensive Compensation System, important in the development of Extreme Programming * VIA C3, a computer processor * ''

Creatures 3 ''Creatures 3'' is the third game in the '' Creatures'' a-life game series made by Creature Labs. In this installment, the Shee have left Albia in a spaceship, the Shee Ark, to search for a more spherical world. The Ark was abandoned by the Shee ...

'', a 1999 video game * '' Crysis 3'', a 2013 video game *

Cluster 3 Cluster II is a space mission of the European Space Agency, with NASA participation, to study the Earth's magnetosphere over the course of nearly two solar cycles. The mission is composed of four identical spacecraft flying in a tetrahedral form ...

, also known as Samba, an ESA satellite

Transportation

Bavarian C III The Bavarian C III engines were steam locomotives of the Royal Bavarian State Railways (''Königlich Bayerische Staatsbahn''). Standard variant The standard variant of the C III was developed from the Class C II. A total of 239 examples were b ...

, a German steam locomotive model *

Bavarian C III (Ostbahn) The Bavarian Class C, later C III, waw a German steam locomotive with the Bavarian Eastern Railway (''Bayrischen Ostbahn'') and Deutsche Reichsbahn. From 1867 a total of 152 examples of this engine were built in Bavaria for the ''Ostbahn''. The f ...

, an 1867 German steam locomotive model * Chevrolet Corvette (C3), the third production design of the Chevrolet Corvette * Circumferential Road 3 or C-3, an arterial road of Manila, Philippines *

Cierva C.3 __NOTOC__ The Cierva C.3 was an experimental autogyro built by Juan de la Cierva in Spain in 1921. It was based on the fuselage of a Sommer monoplane, and was actually completed and tested before that aircraft. The C.3 utilised a single, three-b ...

, a 1921 Spanish experimental autogyro * Citroën C3, a car *

LB&SCR C3 class The London, Brighton and South Coast Railway C3 class was a class of 0-6-0 steam locomotives, intended for heavy freight trains. Ten were built by Brighton railway works in 1906 to the design of Douglas Earle Marsh. History This class was int ...

, a British LB&SCR locomotive *

London Buses route C3 This is a list of Transport for London (TfL) contracted bus routes in London, England, as well as commercial services that enter the Greater London area (except coaches). Bus services in London are operated by Abellio London, Arriva London, ...

, a Transport for London contracted bus route *

C3 (railcar) The C3 is a bi-level coach railroad car built by Kawasaki. These cars began delivery in 1997, ordered by the Metropolitan Transportation Authority for the Long Island Rail Road. The rail cars are pulled and pushed by EMD DE30AC and DM30AC over ...

, a bi-level railcar built by Kawasaki Railcar for the non-electrified branches of the Long Island Rail Road * Nimrod NRA/C3, a 1983 Group C racing car never achieved *

Yamaha C3 List of motorcycles manufactured by Yamaha Motor Company. First bikes * YA-1 built August 1954, produced January 1955. The first bike manufactured by Yamaha was actually a copy of the German DKW RT 125; it had an air-cooled, two-stroke, single ...

, a 2007 liquid cooled 49cc four-stroke motor scooter * Two different ring expressways in Japan where numbered C3: ** Tokyo Gaikan Expressway in Tokyo, Saitama and Chiba Prefectures **

Tōkai-Kanjō Expressway The (lit. Tōkai Ring Expressway) is a toll road in the Tōkai region of Japan. It is owned and managed by Central Nippon Expressway Company. Naming Officially, the route is designated as National Route 475. On some signs, the expressway is re ...

in Aichi, Gifu and Mie Prefectures

Music

Hammond C3 organ The Hammond organ is an electric organ invented by Laurens Hammond and John M. Hanert and first manufactured in 1935. Multiple models have been produced, most of which use sliding drawbars to vary sounds. Until 1975, Hammond organs generated s ...

* High C in music (c3 in European notation) * Low C in music (C3 in American notation) * '' Tha Carter III'', the title of an album by rapper Lil Wayne * C3 Presents, independent American concert promoters

Other uses

C3 (classification) C3 is a para-cycling classification. The class includes people with moderate upper or lower limb dysfunctions and includes cyclists with cerebral palsy, limb impairments and amputations. The UCI recommends this be coded as MC3 or WC3. The class ...

, a para-cycling classification * ''C³'' (light novel), a 2011 Japanese light novel series and anime by Hazuki Minase * C3, a New Zealand logistics company owned by Linx Cargo Care Group * C3, the code for permission to use specific land or premises for dwellings in town and country planning in the United Kingdom * C3, the UEFA Europa League in football * C3, a standard paper size defined in

ISO 216 ISO 216 is an international standard for paper sizes, used around the world except in North America and parts of Latin America. The standard defines the "A", "B" and "C" series of paper sizes, including A4, the most commonly available paper size ...

* Tippmann C-3, a pump-action paintball marker that uses propane gas *

C3 Church Global C3 Church Global, formerly known as Christian City Church International (C3i), is a charismatic movement founded by Phil Pringle and Christine Pringle. The first church was started in Dee Why on the Northern Beaches of Sydney, Australia, and is ...

, a worldwide Pentecostal denomination * C3, a class in FM radio broadcasting in North America * Argus C3, a 35mm rangefinder camera * Nokia C3 (disambiguation), various Nokia cellphones * Caldwell 3 ( NGC 4236), a barred spiral galaxy in Draco *

C3 policing C3 policing or Counter Criminal Continuum Policing is a modification of counter-insurgency ("COIN") methods used by Special Forces (United States Army), U.S. Army Special Forces and adapted for use by civilian law enforcement agencies. The C3 poli ...

, a methodology being employed by police to combat gangs in Springfield, Massachusetts *

Nielsen ratings Nielsen Media Research (NMR) is an American firm that measures media audiences, including television, radio, theatre, films (via the AMC Theatres MAP program), and newspapers. Headquartered in New York City, it is best known for the Nielsen rat ...

that include recorded programs watched three days later *

Championing Community Children Championing Community Children, also known by its members by its abbreviation, C3, is an organization founded by International Children’s Peace Prize laureate Kesz Váldez, who has started the organization in around 2006 in the desire to help ...

, a Philippine charitable organization abbreviated as C3 * Charles Keating III (born 1955), American former swimmer and real estate executive * Charles III (born 1948), King of the United Kingdom and 14 other Commonwealth realms since 2022. * C-III Capital Partners, an

asset management Asset management is a systematic approach to the governance and realization of value from the things that a group or entity is responsible for, over their whole life cycles. It may apply both to tangible assets (physical objects such as buildings ...