- MacDonald, Elvey
- Mansfield, Averil
- Martin, Aubrey John
- Mathew, David
- Mathew, Hugh Pawley
- Mathias, Roland Glyn
- Mathias, William Alun
- Matthews, D. Hugh
- Matthews, Gethin
- McLean, John Charles
- Meredith, David
- Meredith, John Ellis
- Messer, Danna R.
- Miles, Dillwyn
- Moore, Donald
- Morgan, D. Densil
- Morgan, David James
- Morgan, Derec Llwyd
- Morgan, Gerald
- Morgan, Gwyneth
- Morgan, Jill
- Morgan, John
- Morgan, Prys
- Morgan, Richard Harding
- Morgan, Syd
- Morgan, Thomas John
- Morgan, W. John
- Morgan, Walter Thomas
- Morris, Edward Ronald
- Morris, William
- Morris-Jones, Huw
- Mullins, Daniel Joseph