- C.F. Pachuca (Football)
- C&K Basildon Ladies (Football)
- Cadiz (Football)
- Caen (Football)
- Caernarfon Town (Football)
- Cagliari (Football)
- Cairns Taipans (Basketball)
- Cal Poly (American Football)
- Cal State Fullerton (Basketball)
- Caldy (Rugby Union)
- Caleb Plant (Boxing)
- Caleb Truax (Boxing)
- Caledonia Gladiators (Basketball)
- Caledonia Gladiators Women (Basketball)
- Caledonian Braves (Football)
- Calgary Flames (Ice Hockey)
- Calgary Stampeders (Canadian Football)
- Calgary Wild FC (Football)
- California (American Football)
- California (Basketball)
- California Baptist (Basketball)
- California Davis (Basketball)
- California Knights (Cricket)
- California Santa Barbara (Basketball)
- Callum Johnson (Boxing)
- Callum Simpson (Boxing)
- Callum Smith (Boxing)
- Cambodia (Football)
- Cambodia (Cricket)
- Cambridge (Rugby Union)
- Cambridge City Women (Football)
- Cambridge United (Football)
- Cambridge United WFC (Football)
- Cambridge University (Cricket)
- Cambridgeshire (Cricket)
- Cambridgeshire Women (Cricket)
- Cambuur Leeuwarden (Football)
- Camelon Juniors (Football)
- Cameroon (Football)
- Cameroon (Volleyball)
- Cameroon Women (Football)
- Cameroon Women (Volleyball)
- Cameroon Women (Cricket)
- Campbell (American Football)
- Campbelltown City (Football)
- Canada (Ice Hockey)
- Canada (Rugby Union)
- Canada (Football)
- Canada (Tennis)
- Canada (Basketball)
- Canada (Rugby League)
- Canada (Volleyball)
- Canada (Baseball)
- Canada (Cricket)
- Canada Jr Team (Baseball)
- Canada Under-19s (Cricket)
- Canada Women (Football)
- Canada Women (Rugby Union)
- Canada Women (Basketball)
- Canada Women (Lacrosse)
- Canada Women (Hockey)
- Canada Women (Volleyball)
- Canberra (Australian Rules Football)
- Canberra United (Football)
- Candace's Rising Stars (Basketball)
- Canelo Álvarez (Boxing)
- Cangzhou Mighty Lions (Football)
- Cannes (Football)
- Canterbury (Rugby Union)
- Canterbury (Cricket)
- Canterbury Women (Cricket)
- Canterbury Women (Rugby Union)
- Canvey Island (Football)
- Cape Cobras (Cricket)
- Cape Town Blitz (Cricket)
- Cape Town Samp Army (Cricket)
- Cape Verde (Football)
- Cape Verde (Handball)
- Cape Verde (Basketball)
- Cara Diamonds (Cricket)
- Cardiff City (Football)
- Cardiff Demons Women (Rugby League)
- Cardiff Devils (Ice Hockey)
- Cardiff Dragons (Netball)
- Cardiff Met Archers (Basketball)
- Cardiff Metropolitan University (Football)
- Cardiff Rugby (Rugby Union)
- Caribbean Tigers (Cricket)
- Carl Frampton (Boxing)
- Carlisle United (Football)
- Carlos Adames (Boxing)
- Carlos Canizales (Boxing)
- Carlos Cuadras (Boxing)
- Carlos Ocampo (Boxing)
- Carlos Takam (Boxing)
- Carlow (Hurling)
- Carlow (Gaelic Football)
- Carlton (Australian Rules Football)
- Carluke Rovers (Football)
- Carnoustie Panmure (Football)
- Carolina Hurricanes (Ice Hockey)
- Carolina Panthers (American Football)
- Caroline Dubois (Boxing)
- Carshalton Athletic (Football)
- Casa Pia AC (Football)
- Castleford Tigers (Rugby League)
- Castres Olympique (Rugby Union)
- Catalans Dragons (Rugby League)
- Cavalry (Football)
- Cavan (Hurling)
- Cavan (Gaelic Football)
- Cayman Islands (Football)
- Cayman Islands (Netball)
- Cayman Islands (Rugby Union)
- CB Gran Canaria (Basketball)
- CD Aves (Football)
- CD C. Piedade (Football)
- CD Feirense (Football)
- CD Mafra (Football)
- CD Motagua (Football)
- CD Nacional (Football)
- CD Tondela (Football)
- Cecilia Braekhus (Boxing)
- Cedevita Olimpija (Basketball)
- Celta Vigo (Football)
- Celtic (Football)
- Celtic Women (Football)
- Central African Republic (Football)
- Central Arkansas (American Football)
- Central Coast Mariners (Football)
- Central Connecticut State (American Football)
- Central District (Australian Rules Football)
- Central Districts (Cricket)
- Central Districts Women (Cricket)
- Central Girls (Football)
- Central Michigan (American Football)
- Central Michigan (Basketball)
- Central Pulse (Netball)
- Central Punjab (Cricket)
- Central Punjab 2nd XI (Cricket)
- Central Sparks (Cricket)
- Central Zone (Cricket)
- Central Zone Women (Cricket)
- Cercle Brugge K.S.V. (Football)
- Cerro Porteño (Football)
- Cesena (Football)
- CF Montréal (Football)
- CFR Cluj (Football)
- Chad (Football)
- Chambery (Rugby Union)
- Chandigarh (Cricket)
- Chandigarh Champs (Cricket)
- Chandigarh Women (Cricket)
- Changchun Yatai (Football)
- Chantelle Cameron (Boxing)
- Charleroi (Football)
- Charles Martin (Boxing)
- Charleston (Basketball)
- Charleston Battery (Football)
- Charleston Southern (American Football)
- Charlie Edwards (Boxing)
- Charlotte (American Football)
- Charlotte (Basketball)
- Charlotte FC (Football)
- Charlotte Hornets (Basketball)
- Charlton Athletic (Football)
- Charlton Athletic Women (Football)
- Chatham Town Women (Football)
- Chattanooga (American Football)
- Chattanooga (Basketball)
- Chattanooga Red Wolves SC (Football)
- Chattogram (Cricket)
- Chattogram Challengers (Cricket)
- Chattogram Division (Cricket)
- Cheadle Town Stingers Women (Football)
- Cheetahs (Rugby Union)
- Chelmsford (Football)
- Chelsea (Football)
- Chelsea U21 (Football)
- Chelsea Women (Football)
- Cheltenham Town (Football)
- Cheltenham Town Ladies (Football)
- Chengdu Rongcheng (Football)
- Chennai Braves Jaguars (Cricket)
- Chennai Super Kings (Cricket)
- Chepauk Super Gillies (Cricket)
- Cherno More Varna (Football)
- Chesham United (Football)
- Chesham United Ladies (Football)
- Cheshire (Cricket)
- Cheshire Phoenix (Basketball)
- Cheshire Women (Cricket)
- Chester FC (Football)
- Chester-Le-Street Town Ladies (Football)
- Chesterfield (Football)
- Chesterfield Women (Football)
- Chhattisgarh (Cricket)
- Chhattisgarh Women (Cricket)
- Chicago Bears (American Football)
- Chicago Blackhawks (Ice Hockey)
- Chicago Bulls (Basketball)
- Chicago Cubs (Baseball)
- Chicago Fire FC (Football)
- Chicago Hounds (Rugby Union)
- Chicago Sky (Basketball)
- Chicago Stars FC (Football)
- Chicago White Sox (Baseball)
- Chichester City (Football)
- Chichester City Ladies (Football)
- Chiefs (Rugby Union)
- Chievo (Football)
- Chihiro Suzuki (Boxing)
- Chikhura Sachkhere (Football)
- Chilaw Marians Cricket Club (Cricket)
- Chile (Football)
- Chile (Tennis)
- Chile (Rugby Union)
- Chile (Hockey)
- Chile (Handball)
- Chile (Volleyball)
- Chile Women (Football)
- Chile Women (Hockey)
- China (Tennis)
- China (Football)
- China (Basketball)
- China (Volleyball)
- China (Baseball)
- China (Cricket)
- China Women (Football)
- China Women (Cricket)
- China Women (Basketball)
- China Women (Lacrosse)
- China Women (Hockey)
- China Women (Volleyball)
- Chinese Taipei (Tennis)
- Chinese Taipei (Football)
- Chinese Taipei (Baseball)
- Chippenham Town (Football)
- Chittagong Division (Cricket)
- Chittagong Kings (Cricket)
- Chongqing Liangjiang Athletic (Football)
- Chordale Booker (Boxing)
- Chorley (Football)
- Chorley Ladies (Football)
- Chris Algieri (Boxing)
- Chris Arreola (Boxing)
- Chris Billam-Smith (Boxing)
- Chris Bourke (Boxing)
- Chris Colbert (Boxing)
- Chris Eubank Jr (Boxing)
- Chris Howard (Boxing)
- Chris van Heerden (Boxing)
- Christian Hammer (Boxing)
- Christian Mbilli (Boxing)
- Christina Linardatou (Boxing)
- Christopher Diaz (Boxing)
- Chuck's Global Stars (Basketball)
- Cincinnati (American Football)
- Cincinnati Bengals (American Football)
- Cincinnati Reds (Baseball)
- Citadel (American Football)
- Cittadella (Football)
- City Club (Cricket)
- Civil Service Strollers (Football)
- Clachnacuddin (Football)
- Clapton Community FC Women (Football)
- Clare (Hurling)
- Clare (Gaelic Football)
- Claremont (Australian Rules Football)
- Claressa Shields (Boxing)
- Claudio Squeo (Boxing)
- Clemson (American Football)
- Clemson (Basketball)
- Clermont (Football)
- Cleveland Browns (American Football)
- Cleveland Cavaliers (Basketball)
- Cleveland Guardians (Baseball)
- Cleveland Indians (Baseball)
- Cleveland State (Basketball)
- Cliftonville (Football)
- Clovers (Rugby Union)
- Club América (Football)
- Club Atlético Vélez Sarsfield (Football)
- Club Brugge (Football)
- Club León (Football)
- Club Necaxa (Football)
- Club Puebla (Football)
- Club Tijuana (Football)
- Club Tijuana Femenil (Football)
- Clyde (Football)
- Clydebank (Football)
- Coalville Town (Football)
- Coastal Carolina (American Football)
- Coastal Riders (Cricket)
- Colchester United (Football)
- Coldstream (Football)
- Coleraine (Football)
- Colgate (American Football)
- Colgate (Basketball)
- Collingwood (Australian Rules Football)
- Colney Heath Ladies (Football)
- Cologne (Football)
- Colombia (Football)
- Colombia (Tennis)
- Colombia (Baseball)
- Colombia (Volleyball)
- Colombia (Rugby Union)
- Colombia U20 (Football)
- Colombia Women (Lacrosse)
- Colombia Women (Volleyball)
- Colombia Women (Football)
- Colombia Women (Rugby Union)
- Colombo (Cricket)
- Colombo Cricket Club (Cricket)
- Colombo Strikers (Cricket)
- Colomiers (Rugby Union)
- Colorado (American Football)
- Colorado (Basketball)
- Colorado Avalanche (Ice Hockey)
- Colorado Rapids (Football)
- Colorado Rockies (Baseball)
- Colorado Springs Switchbacks FC (Football)
- Colorado State (American Football)
- Colorado State (Basketball)
- Colts Cricket Club (Cricket)
- Columbia (Basketball)
- Columbus Blue Jackets (Ice Hockey)
- Columbus Crew SC (Football)
- Combined Campuses and Colleges (Cricket)
- Combined Nations All Stars (Rugby League)
- Combined NSW and ACT XI (Cricket)
- Comets Women (Football)
- Comilla Victorians (Cricket)
- Como (Football)
- Comoros (Football)
- Concord Rangers (Football)
- Congo (Football)
- Connacht Rugby (Rugby Union)
- Connah's Quay Nomads (Football)
- Connecticut (Basketball)
- Connecticut Sun (Basketball)
- Connecticut Whale (Ice Hockey)
- Conor Benn (Boxing)
- Conor McGregor (Mixed Martial Arts)
- Consett Ladies (Football)
- Constantin Ursu (Boxing)
- Cook Islands (Rugby League)
- Cook Islands (Football)
- Cook Islands Women (Cricket)
- Coomera Colts (Football)
- Cork (Hurling)
- Cork (Gaelic Football)
- Cork City (Football)
- Cornish Pirates (Rugby Union)
- Cornwall (Cricket)
- Cornwall Women (Cricket)
- Coronations (Cricket)
- Corvinul Hunedoara (Football)
- Costa Rica (Football)
- Costa Rica Women (Football)
- Coundon Court Ladies (Football)
- Counties Manukau (Rugby Union)
- Counties Manukau Heat (Rugby Union)
- County Select XI (Cricket)
- Cove Rangers (Football)
- Coventry (Rugby Union)
- Coventry Blaze (Ice Hockey)
- Coventry City (Football)
- Coventry Sphinx Ladies (Football)
- Coventry United Ladies (Football)
- Cowboys (Rugby League)
- Cowboys Women (Rugby League)
- Cowdenbeath (Football)
- CR Flamengo (Football)
- Cracovia (Football)
- Craig Richards (Boxing)
- Craigengower Cricket Club Women (Cricket)
- Crawley Town (Football)
- Crawley Wasps Ladies (Football)
- Cray Valley Paper Mills (Football)
- Creighton (Basketball)
- Cremonese (Football)
- Crewe Alexandra (Football)
- Crewe Alexandra Women (Football)
- Cricket Association of Rupandehi XI (Cricket)
- Cricket Australia XI (Cricket)
- Cricket South Africa Invitation XI (Cricket)
- Cristian González (Boxing)
- Croatia (Football)
- Croatia (Tennis)
- Croatia (Basketball)
- Croatia (Handball)
- Croatia B (Football)
- Croatia U21 (Football)
- Croatia Women (Football)
- Croatia Women (Volleyball)
- Crotone (Football)
- Crusaders (Rugby Union)
- Crusaders (Football)
- Cruz Azul (Football)
- Crvena Zvezda (Football)
- Crvena Zvezda (Basketball)
- Crystal Palace (Football)
- Crystal Palace U21 (Football)
- Crystal Palace Women (Football)
- CS Fola Esch (Football)
- CS Universitatea Craiova (Football)
- CSF Speranta Nisporeni (Football)
- CSKA Moscow (Football)
- CSKA Sofia (Football)
- Cuba (Football)
- Cuba (Volleyball)
- Cuba (Baseball)
- Cukaricki Belgrade (Football)
- Culter (Football)
- Cumberland (Cricket)
- Cumbernauld Colts (Football)
- Cumbria (Cricket)
- Cumbria (Rugby League)
- Cumbria Women (Cricket)
- Cumnock (Football)
- Cupar Hearts (Football)
- Curacao (Football)
- Curzon Ashton (Football)
- Curzon Ashton Women (Football)
- Custio Clayton (Boxing)
- Cyprus (Football)
- Cyprus (Tennis)
- Cyprus U21 (Football)
- Cyprus Women (Football)
- Czech Republic (Football)
- Czech Republic (Tennis)
- Czech Republic (Ice Hockey)
- Czech Republic (Basketball)
- Czech Republic (Baseball)
- Czech Republic (Handball)
- Czech Republic (Volleyball)
- Czech Republic U21 (Football)
- Czech Republic Women (Football)
- Czech Republic Women (Lacrosse)
- Czech Republic Women (Volleyball)
- Czech Republic Women (Basketball)