| Ciedda | A unique name meaning a bright spirit. |
| Cilciuhinn | Servant of the Lord |
| Cilda | Servant of the Lord |
| Cimeilliauc | Servant of the Lord |
| Cimesetli | Servant of the Lord |
| Cinbran | Spear of the Lord |
| Cincenn | Spear of the Lord |
| Cingal | Spear of the Lord |
| Cingen | Spear of the Lord |
| Cingetorix | Conqueror of the Cenimagni tribe, a title given to a Celtic leader |
| Cinglas | Battle-hardened warrior, a Celtic name meaning strong in battle |
| Cingual | From the Cingual tribe, a Celtic name referring to a specific people |
| Cingualan | Descendant of the Cingual tribe, a Celtic name indicating heritage |
| Cinguali | People of the Cingual tribe, a Celtic name referring to a specific group |
| Cini | Small, a Celtic name meaning diminutive or small in size |
| Cinmarch | Battle-lover, a Celtic name meaning fond of war |
| Cinnhor | Fair-haired, a Celtic name referring to physical appearance |
| Cinnor | Fair-haired, a Celtic name meaning having light hair |
| Cinon | A name of uncertain origin. |
| Cintugnatus | Conqueror of the Tuatha Dé Danann, a title given to a Celtic leader |
| Cintusmus | Conqueror of the Tuscan people, a title given to a Celtic leader |
| Cinuchan | Battle-hardened warrior, a Celtic name meaning strong in battle |
| Cinuedu | Battle-lover, a Celtic name meaning fond of war |
| Cinuin | Battle-hardened warrior, a Celtic name meaning strong in battle |
| Cinuoc | Battle-lover, a Celtic name meaning fond of war |
| Ciolla | Battle-hardened warrior, a Celtic name meaning strong in battle |
| Ciorra | Battle-lover, a Celtic name meaning fond of war |
| Cipio | To seize, a Latin name meaning to take or capture |
| Cippa | To seize, a Latin name meaning to take or capture |
| Ciriacus | Belonging to Ciriacus, a Latin name referring to a specific person |
| Cistumucus | Possibly derived from Latin, meaning 'of the chest' or 'breast' |
| Citoc | Possibly derived from Greek, meaning 'of the city' or 'citizen' |
| Ciuarheru | Possibly derived from Latin, meaning 'of the spear' or 'spearman' |
| Clac | Possibly derived from Latin, meaning 'clear' or 'bright' |
| Clacc | Possibly derived from Latin, meaning 'of the lake' or 'lake dweller' |
| Clack | Chatterer; Large Man |
| Claellus | Possibly derived from Latin, meaning 'of the shore' or 'shore dweller' |
| Clarembald | Derived from Old French, meaning 'bright shield' or 'shining protector' |
| Clariance | Derived from Old French, meaning 'bright shield' or 'shining protector' |
| Clarions | Derived from Old French, meaning 'clear voice' or 'loud trumpet' |