| Cisco, Illinois | Cisco, Texas | Cisgender |
| Cisne, Illinois | Cisplatin | Cisplatine War |
| Cissna Park, Illinois | Cissus | Cistaceae |
| Cistanche | Cistanche salsa | Cistanche tubulosa |
| Cisteae | Cistern | Cisterns of Tawila |
| Cisticola juncidis | Cistus | Cistus albidus |
| Cistus ×incanus | Cistus creticus | Cistus heterophyllus |
| Cistus incanus | Cistus ladanifer | Cistus libanotis |
| Cistus monspeliensis | Cistus populifolius | Cistus salviifolius |
| Cisuralian | Citadel | Citadel of Erbil |
| Citadel of the Hồ Dynasty | Citation | Cité de l'Architecture et du Patrimoine |
| Cité de l'espace | CITES | Citharexylum |
| Citharinus | Citi | Citibank |
| Citibank Morocco | Cities of Indonesia | Citipati |
| Citizen journalism | Citizen Kane | Citizen science |
| Citizendium | Citizendium.org | Citizenship |
| Citoyenneté romaine | Citrate | Citric acid |
| Citric acid cycle | Citrix Systems | Citroën |
| Citroën C4 | Citron | Citrullus |
| Citrullus colocynthis | Citrullus lanatus | Citrus |
| Citrus aurantiifolia | Citrus aurantium | Citrus × paradisi |
| Citrus ×aurantifolia | Citrus ×aurantium | Citrus ×bergamia |
| Citrus ×clementina | Citrus ×limon | Citrus ×paradisi |
| Citrus ×sinensis | Citrus ×tangerina | Citrus clementina |
| Citrus greening disease | Citrus japonica | Citrus limettioides |
| Citrus maxima | Citrus medica | Citrus medica var. sarcodactylis |
| Citrus production | Citrus psorosis virus | Citrus reticulata |
| Citrus reticulata × sinensis | Citrus tangerina | Citrus tristeza virus |
| Cittaslow | City | City bicycle |
| City block | City car | City Connection |
| City designated by government ordinance | City Football Group | City Hunter |
| City life (لعبة) | City Life (video game) | City Lights |
| City Manager | City marketing | City network |
| City of Arts and Sciences | City of Ember | City of God (2002 film) |
| City of Life | City of Life and Death | City of London |
| City of Manchester Stadium | City of the Dead (Cairo) | City Point, Wisconsin |
| City Protocol | City Slickers | City University London |
| City University of New York | City wiki | City Year |
| City-building game | City-state | Ciutat de Palma |
| Civetone | CIVETS | Civettictis civetta |
| Civic intelligence | Civic political culture | Civics |
| Civil and political rights | Civil authority | Civil aviation |
| Civil Aviation Administration of China | Civil Aviation Affairs | Civil Aviation and Meteorological Authority of Yemen |
| Civil Aviation Authority (United Kingdom) | Civil code | Civil discourse |
| Civil disobedience | Civil engineering | Civil Guard (Spain) |
| Civil law (legal system) | Civil liberties | Civil registry |
| Civil rights referendum | Civil society | Civil uprising phase of the Syrian Civil War |
| Civil war in Afghanistan (1989-1992) | Civil war in Afghanistan (1989–92) | Civil war in Afghanistan (1992-1996) |
| Civil war in Afghanistan (1992–96) | Civil war in Afghanistan (1996-2001) | Civil war in Afghanistan (1996–2001) |
| Civil war in Tajikistan | Civil-military operations | Civilian |
| Civilian control of the military | Civilisées | Civilization |
| Civilization (series) | Civilization V | Civilization V: Brave New World |
| Civilized core | Civitas Popthensis | Cizre |
| CJ Parker (wrestler) | CJCUC | CKM matrix |
| Cl | Claddagh ring | Cladding (construction) |
| Cladistics | Cladium mariscus | Cladobranchia |
| Cladocera | Cladorhynchus | Cladorhynchus leucocephalus |
| Cladosporium | Cladrastis kentukea | Claflin, Kansas |
| Claiborne County, Tennessee | Claiborne Parish, Louisiana | Claim rights and liberty rights |
| Claimed moons of Earth | Clair Cameron Patterson | Claire City, South Dakota |
| Claire Danes | Claire Etcherelli | Claire Holt |
| Claire Lee Chennault | Claire Redfield | Clairmarais |
| Clairton, Pennsylvania | Clam AntiVirus | Clam Falls, Wisconsin |
| Clam Lake Township, Michigan | Clam Union Township, Michigan | Clamator |
| Clamator coromandus | Clamator glandarius | Clamator jacobinus |
| ClamAV | CLAMP | ClamWin |
| ClamWin Antivirus | Clancy Brown | Clandestine abuse |
| Clanga clanga | Clanga pomarina | Clangula hyemalis |
| Clans, Alpes-Maritimes | Clapper bridge | Clapperboard |
| Clara Barton | Clara Basiana | Clara Bow |
| Clara City, Minnesota | Clara Janés | Clara Khoury |
| Clara Zetkin | Clarabelle Cow | Clarín (Argentine newspaper) |
| Clare Boothe Luce | Clare County, Michigan | Clare, Iowa |
| Clare, Michigan | Clare, New York | Claremont, Illinois |
| Claremont, Minnesota | Claremont, New Hampshire | Claremont, North Carolina |
| Claremont, South Dakota | Claremont, Virginia | Claremore, Oklahoma |
| Clarence (2014 TV series) | Clarence Acuña | Clarence Day |
| Clarence Goodson | Clarence King | Clarence L. Johnson |
| Clarence Nash | Clarence Seedorf | Clarence Township, Michigan |
| Clarence Williams III | Clarence, Iowa | Clarence, New York |
| Clarendon Hills, Illinois | Clarendon Township, Michigan | Clarendon, Arkansas |
| Clarendon, New York | Clarendon, Quebec | Clarendon, Texas |
| Clarendon, Vermont | Clarias batrachus | Clariden |
| Clariidae | CLARINASE | Clarinda, Iowa |
| Clarinet | Clarington, Ohio | Clarion County, Pennsylvania |
| Clarion, Iowa | Clarissa, Minnesota | Clarithromycin |
| Clark County, Indiana | Clark County, Wisconsin | Clark Duke |
| Clark Gable | Clark International Airport | Clark Johnson |
| Clark L. Hull | Clark Township, Michigan | Clark, South Dakota |
| Clarkdale, Arizona | Clarke Carlisle | Clarke County, Alabama |
| Clarke's three laws | Clarkedale, Arkansas | Clarkesville, Georgia |
| Clarkfield, Minnesota | Clarkia amoena | Clarks Grove, Minnesota |
| Clarks Hill, Indiana | Clarks, Nebraska | Clarksburg, Massachusetts |
| Clarksburg, Ohio | Clarksburg, Tennessee | Clarksburg, West Virginia |
| Clarksdale, Mississippi | Clarkson, Kentucky | Clarkson, New York |
| Clarkston, Georgia | Clarkston, Michigan | Clarkston, Utah |
| Clarkston, Washington | Clarkstown, New York | Clarksville City, Texas |
| Clarksville, Allegany County, New York | Clarksville, Arkansas | Clarksville, Indiana |
| Clarksville, Iowa | Clarksville, Michigan | Clarksville, New Hampshire |
| Clarksville, Ohio | Clarksville, Tennessee | Clarksville, Texas |
