| Mearr | A name meaning a swift or fast person. |
| Meave | Joy. The name of an early queen of Connaught. |
| Meeda | A name meaning a helpful person |
| Megan | Form Of Margaret; Form of Margaret, meaning resembling a pearl / the child of light; Pearl; Soft And Gentle; Strong and capable; Variant of Margaret: Pearl.; Variant of Margaret: Child of light. Famous Bearer: Margaret Thatcher, former Prime Minister of |
| Megdn | A variant of the name Megan |
| Meghan | Pearl; Strong and capable |
| Meinwen | fair and slender |
| Melrone | Serves Saint Ruadhan |
| Melvin | Chief; A friend who offers counsel; Leader; Mill Worker; Strong friend |
| Merna | A name meaning tender or beloved one. |
| Mide | A name of Irish origin meaning a sweet singer. |
| Miles | A soldier or merciful person. |
| Min | smooth: fine: small. |
| Mitchel | Form of Michael Who is like God? |
| Mitchell | Form of Michael Who is like God? |
| Mogue | Name of a saint |
| Moira | A name meaning star of the sea. |
| Moire | A fabric with a wavy pattern. |
| Molan | Servant of the storm |
| Molli | From the Gaelic Maili which is a pet form of Mary bitter. |
| Mollie | From the Gaelic Maili which is a pet form of Mary bitter. |
| Molloy | Descendant of the redhaired. |
| Mona | Gathers jimson weed seed (Miwok); Gathered of the seed of a jimson weed; Hearkening; A jealous man; Lady.; Loner.; Noble; Noblewoman; One who is born into the nobility; Royal; Solitary. |
| Monca | A variant of the name Monica. |
| Moncha | A variant of Monica meaning advisor. |
| Monohan | One who captures the human heart. |
| Mooney | One who is wealthy and lucky. |
| Mor | Derived from the Hebrew word for myrrh. |
| Morain | Derived from the Gaelic word for moorland. |
| Moran | An Irish name meaning descendant of sea. |
| More | One who lives on the moorland. |
| Morella | Derived from the dark nightshade plant. |
| Morgandy | A name meaning dweller by the sea. |
| Morgayne | Medieval form of Welsh Morcan meaning bright sea. |
| Moriarty | Derived from the Gaelic for sea warrior. |
| Morrin | Meaning the son of the mariner. |
| Morrissey | Choice of the sea |
| Moyna | A small, beautiful singing bird. |
| Mrie | fruitful, flourishing |
| Muadhnait | A person who is well protected. |