| Name | Group | Language of Origin | Languages of Use | Meaning/Translation or Related Words | US 2024 |
| Cleophas | Cleopas/Cleopha | Old Greek | English | glory of the father | |
| Cleto | Anacletus | Old Greek | Portuguese, Spanish, Italian | called on, invoked | |
| Cletus | Cletus | Old Greek | English | famous | |
| Cleve | Clive | Old English | English | Words: cliff | |
| Cliff | Clifford | Old English | English | Words: cliff / ford | |
| Cliff | Clive | Old English | English | Words: cliff | |
| Clifford | Clifford | Old English | English | Words: cliff / ford | |
| Clifton | Clifton | Old English | English | town by a cliff | |
| Clint | Clinton | Old English | English | Words: town, settlement, homestead | |
| Clinton | Clinton | Old English | English | Words: town, settlement, homestead | |
| Clirim | Clirim | Albanian | Albanian | liberated | |
| Clive | Clive | Old English | English | Words: cliff | |
| Clodomiro | Clodomiro | Old High German | Portuguese, Spanish | Words: loud, famous / famous, well-known | |
| Clotario | Lothar | Old High German | Portuguese, Spanish, Italian | Words: loud, famous / army, warrior | |
| Clyde | Clyde | Scottish | English, Scottish | | #727 |
| Coby | Jacob/Jacqueline/Jakoba | Hebrew | English | Yahweh may protect; holder of the heel; supplanter | |
| Codey | Cody | Old Irish | English | Words: son | |
| Codi | Cody | Old Irish | English | Words: son | |
| Codie | Cody | Old Irish | English | Words: son | |
| Cody | Cody | Old Irish | English, Irish | Words: son | #289 |
| Coen | Conrad/Konrada | Old High German | Dutch | Words: bold / counsel, advice, advisor | |
| Cohen | Cohen | Hebrew | English | priest | #239 |
| Coinneach | Ken/Kenna | Celtic | Scottish | the handsome | |
| Colby | Colby | Old English | English | coal town | #581 |
| Cole | Cole | Old English | English | the black | #162 |
| Coleman | Columbano | Latin | English, Irish | dove | |
| Coleson | Colson | English | English | son of Cole | #914 |
| Cölestin | Celestine/Cölestina | Latin | German | heavenly, of the sky | |
| Cölestinus | Celestine/Cölestina | Latin | German | heavenly, of the sky | |
| Coleton | Colton | Old English | English | coal town | |
| Colin | Nicholas/Nicole | Old Greek | English | victory of the people | #334 |
| Collin | Nicholas/Nicole | Old Greek | English | victory of the people | #489 |
| Colm | Callum | Latin | Irish | dove | |
| Colman | Columbano | Latin | Irish | dove | |
| Coloman | Koloman | Celtic | German | maybe hermit | |
| Colombano | Columbano | Latin | Italian | dove | |
| Colsen | Colson | English | English | son of Cole | #631 |
| Colson | Colson | English | | son of Cole | #353 |
| Colt | Colton | Old English | English | coal town | #276 |
| Colten | Colton | Old English | English | coal town | #895 |
| Colter | Colter | English | English | herder of horses | #218 |
| Colton | Colton | Old English | English | coal town | #98 |
| Columban | Columbano | Latin | English | dove | |
| Columbano | Columbano | Latin | Portuguese, Spanish | dove | |
| Côme | Cosmo/Cosima | Old Greek | French | | |
| Conan | Conan | Celtic | English | maybe the great (?); hound | |
| Connell | Connell | Unknown | English | | |
| Conner | Connor | Old Irish | English | maybe dog lover | #781 |
| Connor | Connor | Old Irish | English, Irish | maybe dog lover | #136 |
| Conny | Conrad/Konrada | Old High German | German | Words: bold / counsel, advice, advisor | |
| Conor | Connor | Old Irish | English, Irish | maybe dog lover | #707 |
| Conrad | Conrad/Konrada | Old High German | German, English | Words: bold / counsel, advice, advisor | #469 |
| Conradin | Conrad/Konrada | Old High German | German | Words: bold / counsel, advice, advisor | |
| Conrado | Conrad/Konrada | Old High German | Spanish | Words: bold / counsel, advice, advisor | |
| Conradus | Conrad/Konrada | Old High German | Dutch | Words: bold / counsel, advice, advisor | |
| Consalvo | Gonzalo | Old High German | Italian | Words: fight | |
| Constantin | Konstantin/Konstanze | Latin | French | the steadfast | |
| Constantine | Konstantin/Konstanze | Latin | English | the steadfast | |
| Cooper | Cooper | Old English | English | cooper, barrel maker | #50 |
| Corban | Corvin | Latin | English | Words: raven | |
| Corbin | Corvin | Latin | English | Words: raven | #473 |
| Corbinian | Korbinian | Old High German | German | Words: raven / raven | |
| Cordell | Cordell | Old English | English | maker of cord, seller of cord | |
| Corentin | Corentin/Corentine | Celtic | German, French, Breton | Words: storm | |
| Corey | Corey/Corey | Latin | English | Words: raven / ravine | #678 |
| Corin | Quirin/Quirina | Latin | French | | |
| Cormac | Cormac | Old Irish | Irish | son of the charioteer | |
| Corneille | Cornelius/Cornelia | Latin | French | Words: horn | |
| Cornel | Cornelius/Cornelia | Latin | German | Words: horn | |
| Cornelio | Cornelius/Cornelia | Latin | Spanish, Italian | Words: horn | |
| Cornelis | Cornelius/Cornelia | Latin | German, Dutch | Words: horn | |
| Cornelius | Cornelius/Cornelia | Latin | German | Words: horn | |
| Cornell | Cornelius/Cornelia | Latin | English | Words: horn | |
| Corrado | Conrad/Konrada | Old High German | Italian | Words: bold / counsel, advice, advisor | |
| Corsin | Corsin | Unknown | Rhaeto-Romanic | | |
| Cortez | Curtis | Old French | Spanish, English | courtly, courteous | |
| Cortney | Courtney/Courtney | Old French | English | Words: short / nose | |
| Corvin | Corvin | Latin | English | Words: raven | |
| Cory | Corey/Corey | Latin | English | Words: raven / ravine | |
| Cosimo | Cosmo/Cosima | Old Greek | Italian | | |
| Cosmin | Cosmo/Cosima | Old Greek | Romanian | | |
| Cosmo | Cosmo/Cosima | Old Greek | German, Italian, English | | |
| Costante | Konstantin/Konstanze | Latin | Italian | the steadfast | |
| Costantino | Konstantin/Konstanze | Latin | Italian | the steadfast | |
| Costanzo | Konstantin/Konstanze | Latin | Italian | the steadfast | |
| Coty | Coty | Old French | English | coast, river bank | |
| Courtney | Courtney/Courtney | Old French | German | Words: short / nose | |
| Coy | Coy | Unknown | English | | |
| Craig | Craig | Old Irish | English, Scottish | Words: rock | |
| Creed | Creed | Latin | English | creed, belief | #612 |
| Crescenzio | Crescenzio/Crescentia | Latin | Italian | the growing | |
| Crew | Carew | Welsh | English | Words: castle, fortress | #250 |
| Crisanto | Crisanto | Old Greek | Spanish, Tagalog | golden Flower; chrysanthemum | |
| Crispin | Crispin/Crispina | Latin | German, English | curly haired | |
| Crispino | Crispin/Crispina | Latin | Italian | curly haired | |
| Cristian | Christian/Christine | Latin | Spanish | Christian, disciple of Christ | #320 |
| Cristián | Christian/Christine | Latin | Spanish | Christian, disciple of Christ | |
| Cristiano | Christian/Christine | Latin | Italian | Christian, disciple of Christ | |
| Cristobal | Christoph | Old Greek | English | carrying Christ | |
| Cristóbal | Christoph | Old Greek | Spanish | carrying Christ | |