| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 121 | Caerwyn | Welsh | White fortress. | M | |
| 122 | Cai | Welsh | A diminutive of Cajus, frequently used as an independent name in Wales. Rejoicer. | M | |
| 123 | Cain | Welsh | Clear water. | M | |
| 124 | Caio | Welsh | Variant of Cai: Joy. | M | |
| 125 | Caius | Welsh | Variant of Cai: Joy. | M | |
| 126 | Calcas | Welsh | Legendary son of Caw. | M | |
| 127 | CaledvwIch | Welsh | Legendary Excalibur, King Arthur's sword. | M | |
| 128 | Camedyr | Welsh | Legendary son of Govynyon. | M | |
| 129 | Cant | Welsh | White. | M | |
| 130 | Caradawg | Welsh | Legendary father of Eudav. | M | |
| 131 | Caradoc | Welsh | Affection; amiable. Famous bearer: First century British king Caradoc, better known as King Caractacus. | M | |
| 132 | Caradog | Welsh | Variant of Caradoc: Affection; amiable. | M | |
| 133 | Carey | Welsh | Near the castle; from the castle. | M | |
| 134 | Carne | Welsh | Variant of English surname Cairn meaning landmark or memorial of piled-up stones. | M | |
| 135 | Carthage | Welsh | Variant of Caradoc: Affection; amiable. | M | |
| 136 | Carwyn | Welsh | Variant of Caerwyn: White fortress. | M | |
| 137 | Cary | Welsh | From the castle. 'Loving.'. | M | |
| 138 | Cas | Welsh | Legendary son of Seidi. | M | |
| 139 | Casnar | Welsh | Legendary nobleman. | M | |
| 140 | Cass | Welsh | Curly-headed. | M | |