| Clay | Man | English Names |
| Clayland | Man | English Names |
| Clayne | Unisex | English Names |
| Clayton | Man | English Names |
| Clea | Woman | Greek Names |
| Cleantha | Woman | Greek Names |
| Cleary | Unisex | English Names |
| Cleatus | Man | Greek Names |
| Cleavant | Man | English Names |
| Cleave | Man | English Names |
| Cleavon | Man | English Names |
| Cledith | Unisex | American Names |
| Cledwyn | Man | Welsh Names |
| Clee | Unisex | English Names |
| Clef | Unisex | French Names |
| Clegg | Unisex | English Names |
| Clem | Man | English Names |
| Clemance | Woman | French Names |
| Clematis | Woman | English Names |
| Cleme | Man | Spanish Names |