C
- Richard Carew, translator and antiquary
- Elizabeth Carne, geologist
- James Power Carne, Victoria Cross DSO, Lieutenant Colonel of the 1st Gloucestershire Regiment who was an instrumental figure at the Battle of the Imjin River in the Korean War
- Joseph Carne, geologist, industrialist and Fellow of the Royal Society
- John Carter, smuggler known as the "King of Prussia", who operated from Prussia Cove
- Charles Causley, poet
- William Clift, naturalist and Fellow of the Royal Society
- Joseph Henry Collins, mining engineer, mineralogist and geologist
- Myrna Combellack academic researcher and writer of Cornish history
- Constantine of Cornwall, Cornish ruler and saint
- William Cookworthy, discoverer of china clay (kaolinite) in Cornwall
- Saint Corentin, missionary to Brittany
- Corineus, the legendary founder of Cornwall in Geoffrey of Monmouth's Historia Regum Britanniae
- Jonathan Couch, naturalist and physician
- Richard Quiller Couch, naturalist
- John Kevin Curtice, political scientist
Read more about this topic: List Of People From Cornwall