- CADELL ap GRUFFYDD (d. 1175)
- CADFAN (fl. 550?), saint
- CADFAN, prince
- CADFAN - see WILLIAMS, HUGH
- CADFAN GWYNEDD - see HUGHES, HUGH
- CADOG saint (fl. c. 450), one of the chief figures of the Celtic church in Wales
- CADRAWD - see EVANS, THOMAS CHRISTOPHER
- CADVAN - see DAVIES, JOHN CADVAN
- CADWALADER, JOHN (fl. second half of 18th century), ballad and interlude writer - see KADWALADR, SION
- CADWALADER, SION (fl. second half of 18th century), ballad and interlude writer - see KADWALADR, SION
- CADWALADER, SIONYN (fl. second half of 18th century), ballad and interlude writer - see KADWALADR, SION
- CADWALADR (d. 1172), prince
- CADWALADR (d. 664), prince
- CADWALADR ap RHYS TREFNANT (fl. 1600), poet
- CADWALADR CESAIL (fl. 1620), poet
- CADWALADR, Sir RHYS (fl. 1666-1690), cleric and poet
- CADWALADR, BETSI - see DAVIS, ELIZABETH
- CADWALADR, DAFYDD (1752 - 1834), Calvinistic Methodist preacher
- CADWALADR, EDWARD (fl. 16th century), poet
- CADWALADR, ELLIS (fl. 1707-40), poet
- CADWALADR, HUW (fl. 17th century), poet
- CADWALADR, ROGER (1566 - 1610), seminary priest and martyr
- CADWALLON (d. 633), prince
- CADWALLON Maelienydd - see ELSTAN GLODRYDD
- CADWALLON ap CARADOG ap IESTYN - see MORGAN ap CARADOG ap IESTYN
- CADWGAN (d. 1111), prince
- CADWGAN (d. 1241), bishop of Bangor
- CADWGAN DELYNOR (fl. at end of 14th century, and beginning of the 15th century), musician
- CADWGAN FFOL (fl. 13th century), bard
- CAERFALLWCH - see EDWARDS, THOMAS
- CAFFO Saint - see CYBI, Saint
- CAIN Saint - see KEYNE, Saint
- CALEDFRYN - see WILLIAMS, WILLIAM
- CALLAGHAN, LEONARD JAMES (1912 - 2005), politician
- CAMPBELL, BETTY - see CAMPBELL, RACHEL ELIZABETH
- CAMPBELL, ELIZA CONSTANTIA (1796 - 1864), author
- CAMPBELL, FREDERICK ARCHIBALD VAUGHAN, viscount Emlyn (1847-1898), earl Cawdor (1898-1911)
- CAMPBELL, RACHEL ELIZABETH (1934 - 2017), teacher and community activist
- CAMROSE, 1st Viscount - see BERRY
- CANNON, MARTHA MARIA HUGHES (1857 - 1932), doctor and politician
- CANRHAWDFARDD - see JONES, THOMAS
- CAPELULO - see WILLIAMS, THOMAS
- CARADAWC - see BEVAN, THOMAS
- CARADAWC Y FENNI - see BEVAN, THOMAS
- CARADAWG - see STEPHENS, THOMAS
- CARADOG (fl. 1135) LLANCARFAN, man of letters
- CARADOG - see JONES, GRIFFITH RHYS
- CARADOG - see JONES, JOSEPH
- CARADOG ap GRUFFYDD ap RHYDDERCH (d. 1081)
- CARADOG ap IESTYN (fl. 1130), founder of the family of 'Avene' in Glamorgan