| Name | Speciality |
| M | |
| Dr Declan Magee | Anaesthesia |
| Dr Vincent Maher | Cardiology |
| Dr Rosemarie Manning | Paediatric Respiratory/Cardiology Medicine |
| Dr Ciara Martin | Paediatric Emergency Medicine |
| Dr Dominick McCabe | Neurology |
| Mr Tom McCarthy | Orthopaedics |
| Dr Ray McDermott | Medical Oncology |
| Mr Ted McDermott | Urology |
| Dr Paul McDonagh | Anaesthesia |
| Dr Denise McDonald | Community Child Health/Neurology |
| Dr John McDonnell | Anaesthesia |
| Dr Jacinta McElligott | Rehabilitation Medicine |
| Mr John McElwain | Orthopaedics |
| Dr John McHugh | Haematology |
| Dr Paula McKay | Psychiatry |
| Mr Johnny McKenna | Orthopaedics |
| Dr Tom McMonagle | Psychiatry |
| Dr Paul McNally | Paediatric Respiratory Medicine |
| Dr Deirdre McNamara | Gastroenterology |
| Mr Donald McShane | Ear, Nose and Throat |
| Dr George Mellotte | Nephrology |
| Dr Edward Moloney | Respiratory Medicine |
| Mr David Moore | Orthopaedics |
| Dr Kevin Moore | Endocrinology |
| Dr David Moore | Cardiology |
| Dr Tom Moran | Psychiatry |
| Dr Paul Moriarty | Ophthalmology |
| Mr Seamus Morris | Orthopaedics |
| Dr David Mulcahy | Cardiology |
| Dr Ronan Mullan | Rheumatology |
| Dr Raymond Murphy | Neurology |
| Dr Philip Murphy | Microbiology |
| Dr Denis Murphy | Psychiatry |
| Dr Cliona Murphy | Gynaecology |