M
- Jessica Mann, crime writer
- Mark of Cornwall, ruler of Cornwall in the legend of Tristan and Iseult (see also Tristan)
- Nigel Martyn, former England footballer
- John Mayow, physiologist
- Rory McGrath, comedian
- Kevin Miller, footballer who played for Crystal Palace, Birmingham City and Watford
- Chris Morris, footballer who played for Glasgow Celtic and Sheffield Wednesday
- Matthew Paul Moyle, meteorologist and mining writer
- David Mudd, Conservative Party MP, local historian and broadcaster
- William Murdoch, engineer, inventor and sometime Cornish resident
Read more about this topic: List Of People From Cornwall