| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 141 | Cathmor | Gaelic | Great warrior. | M | |
| 142 | Cathmore | Gaelic | Great warrior. | M | |
| 143 | Cavan | Gaelic | Handsome. | M | |
| 144 | Ceallach | Gaelic | Warrior. | M | |
| 145 | Ceannfhionn | Gaelic | Blond. | M | |
| 146 | Cearbhallan | Gaelic | Small champion. | M | |
| 147 | Cearnach | Gaelic | Victorious. | M | |
| 148 | Ceileachan | Gaelic | Little champion. | M | |
| 149 | Cein | Gaelic | Ancient. | M | |
| 150 | Cerin | Gaelic | Little dark one. | M | |
| 151 | Charraigaich | Gaelic | Rocky headland. | M | |
| 152 | Choilleich | Gaelic | Guards the forest. | M | |
| 153 | Cian | Gaelic | Ancient. | M | |
| 154 | Ciardubhan | Gaelic | Little black one. | M | |
| 155 | Cinnard | Gaelic | From the high hill. | M | |
| 156 | Cinneididh | Gaelic | Helmeted. | M | |
| 157 | Cinnfhail | Gaelic | From the head of the cliff. | M | |
| 158 | Cleary | Gaelic | Scholar. | M | |
| 159 | Cleirach | Gaelic | Scholar. | M | |
| 160 | Clunainach | Gaelic | From the meadow. | M | |