| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Cosima | - | Italian | ||
| Cosimo | KAW-zee-maw, KO-zi-mo | Italian | ||
| Cosma | - | Italian | ||
| Cosmas | - | Ancient Greek (Latinized) | ||
| Cosmin | - | Romanian | ||
| Cosmina | - | Romanian | ||
| Costache | kos-TAH-ke | Romanian | ||
| Costantino | - | Italian | ||
| Costanzo | - | Italian | ||
| Costel | ko-STEL | Romanian | ||
| CosticĂ | kos-TEE-kə | Romanian | ||
| Costin | - | Romanian | ||
| Cowessess | - | Native American, Ojibwe | ||
| Cree | KREE | English (Rare) | ||
| Creighton | KRAY-tən | English (Rare) |