C3

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
Apolipoprotein C3, a human very low density lipoprotein
ATC code C03 Diuretics, a subgroup of the Anatomical Therapeutic Chemical Classification System
Castavinol C3, a natural phenolic compound found in red wines
Cytochrome-c3 hydrogenase, 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
Complement component 3, a protein of the innate immune system
C03, Malignant neoplasm of gum ICD-10 code
C3 Collaborating for Health, a health-promotion NGO

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 designation for several German World War I and World War II armed reconnaissance aircraft
- AEG C.III
- AGO C.III, a reconnaissance biplane of World War I
- Albatros C.III
- DFW C.III, 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 WWII Imperial Japanese Navy cargo carrier submarine
Spanish submarine C-3
HMS C3, a 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 United States C class submarine
USS Baltimore (C-3), a protected cruiser of the United States Navy
Garda Crime & Security Branch (CSB), domestic security agency of Ireland's national police, formerly "C3"
C3 Howitzer, a lengthened variant of the M101 used by the Canadian Armed Forces

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, a molecule found in interstellar space, and for cyclopropatriene
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, a video game
Cluster 3, also known as Samba, an ESA satellite

C3 (classification), a para-cycling classification
C3 (light novel), a Japanese light novel series and anime by Hazuki Minase
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
Tippmann C-3, a pump-action paintball marker that uses propane gas
C3 Church Global, a worldwide Pentecostal denomination
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, a methodology being employed by police to combat gangs in Springfield, Massachusetts
Nielsen ratings that include recorded programs watched three days later
Championing Community Children, a Philippine charitable organization abbreviated as C3