| Name |
Pronunciation |
Meaning |
English Spelling |
Gender |
| Mac Bethad, Mac Beatha | (mok-BA-ha) | righteous | | M |
| Mac Caille, Mac Coille | (mok-KIL-ee) | son of the wood | | M |
| Mac Cáirthinn | (mok-KAR-hin) | son of the rowan tree | Macartan | M |
| Mac Con | (mac-CON) | son of a wolf | Maccon | M |
| Mac Cuilind, Mac Cuilinn | (mok-KIL-in) | son of the holly | MacKillan | M |
| Mac Dara | (mok-DA-ra) | son of the oak | | M |
| Mac Laisre | (mok-LOS-ra) | son of flame | | M |
| Mac Nisse | (mok-NEES-a) | son of Ness | | M |
| Mac Raith | (mok-RAH) | son of grace | McGrath, McGraw | M |
| Mac Táil | (mok-TAWL) | son of adze | | M |
| Macha | (MOK-a) | | | F |
| Máedóc, Maodhóc | (MAY-owg) | | | M |
| Máel Anfaid, Maolanaithe | (MAYL-an-a-ha) | devotee of the storm | | M |
| Máel Coluim, Maolcholuim | (mayl-KUL-im) | servant of St. Colmcille | Malcolm | M |
| Máel Dúin, Maol Dúin | (mayl-DOON) | warrior of the fortress | Maoldúin, Muldoon | M |
| Máel Eoin, Maol Eoin | (meyl-OWN) | devotee of St. John | Maoileoin, Malone | M |
| Máel Ísu, Maol Íosa | (meyl-EE-sa) | "devotee of Jesus" | | M |
| Máel Máedóc, Maolmhaodhóg | (meyl-VEY-ohg) | "devotee of St Máedóc" | Malachy | M |
| Máel Mórda, Maol Mhórdha | (meyl-VOR-a) | from mórda, "great, haughty" | Malachy | M |
| Máel Muad, Maol Mhuadh | (meyl-VOO-a) | from muad, "noble or proud" | Molloy | M |
| Máel Muire, Maol Mhuire | (meyl-VEE-ra) | "devotee of Mary" | | M/F |
| Máel Odrán, Maol Odhráin, Maolóráin | (meyl-OH-rawn) | "devotee of St Odrán" | | M |
| Máel Ruanaid, Maolruanaidh, Maolruanaí | (meyl-ROO-an-ee) | "from ruanaid, a champion, a strong man" | Mulroney | M |
| Máel Sechnaill, Máel Sechlainn, Máelechlainn,
M'Lachlainn | (meyl-AWCK-lin) | "devotee of St Sechnall" | | M |
| Máelán, Maolán | (MEYL-awn) | "a warrior" | Maoláin, Mullin | M |
| Máen, Maon | (meyn) | "silent" | | M/F |
| Máenach, Maonach | (MEYN-ack) | from Máen | Mooney, Meany | M |
| Magnus, Maghnus, Mánus | (MAN-us) | from Latin, magnus, "great" | | M |
| Maílín, Maolín | (mel-EEN) | | | M |
| Mainchíne, Mainchín | (MAN-heen) | dim. of manach, "a monk" | | M |
| Maine | (MAN-ee) | | Manny | M |
| Máire | (MAW-ree) | borrowing of Biblical Mary | Moira, Maura, Maureen | F |
| Maithgen, Maithghen, Maithín | (ma-HEEN) | "son of the bear" | | M |
| Maiú, Maidiú | (MAD-yew) | borrowing of Biblical "Matthew" | | M |
| Manchán | (mon-KAWN) | dim. of manach, "a monk" | | M |
| Marcán | (mor-KAWN) | from marc "a steed" | | M |
| Margo, Marga | (MAR-ga) | | | F |
| Márgrég, Máirgrég, Máirgréc,
Máirghréad, Máiréad | (MEYR-ayd) | borrowing of Latin margarita, "pearl" | Peig, Peigí | F |
| Martan | (MART-in) | form of Martin | Mártín | M |
| Martha | (MARTH-a) | borrowing of Biblical Martha | | F |
| Matha | (MAH-ha) | | | M |
| Mathgamain, Mathghamhain, Mathúin | (mo-HOON) | "bear-calf" | Mahoney, Mahon | M |
| Mechar, Meachar | (MAW-her) | "fine, majestic" | Maher | M |
| Medb, Meadhbh, Meadhbha, Méabh | (MAYV) | intoxicating, she who makes men drunk" | Maeve | F |
| Mel | (MEL) | | | M |
| Mell, Mella, Meall, Mealla | (MAL) | "lightning" | | F |
| Mellán, Meallán | (mel-
LAWN) | | Mallin, Mallon | M |
| Menma, Meanma | (MAN-ma) | "high spirit, courage" | | M |
| Miadach, Miadhach, Miach | (MEE-ack) | "honourable, proud" | | M/F |
| Míchél, Mícheál | (MEE-hawl) | borrowing of Biblical Michael | | M |
| Midabair, Miodhabhair, Míodhúir | (MEE-oor) | | | F |
| Midir | (MID-eer) | midiur, "I judge" | | M |
| Midnat, Miodhnait, Míonait | (MEE-nit) | | | F |
| Mínchloth | (MIN-kloh) | "of gentle reputation" | | F |
| MoBí, Moibhí | (mu-VEE) | pet form of Berchán and Brénainn | | M |
| Mo Cháemmóc, Mochaomhóg | (mu-KEYV-og) | pet form of Cáemgen and Cáemán | | M |
| Mo Cholla, Mocholla | (mu-KUL-a) | | | M |
| Mo Chonna, Mochonna | (mu-KUN-a) | | | M |
| Mo Chua, Mochua | (mu-KOO-a) | pet form of Crónán | | ? |
| Mo Chumma, Mochuma | (mu-KOOM-a) | pet form of Colmán | | ? |
| Mo Chutu, Mochuda | (mu-KOOT-a) | pet form of Carthach | | M |
| Mo Laisse, Molaisse | (mu-LOS-a) | pet form of Laisrén | | M |
| Mo Lua, Molua | (mu-LOO-a) | pet form of Lugaid | | M |
| Mochta | (MUK-ta) | "great" | | M |
| Móirne | (MOR-na) | derivative of Mór | | F |
| Moncha | (MUN-ka) | | | F |
| Mongán | (mun-GAWN) | from mong, "head of long and abundant hair" | Mongáin, Mangan | M |
| Mongfind, Moingfhionn, Moingionn | (MUNG-in) | "fair-haired" | | F |
| Mór | (MOR) | "tall, great" | | F |
| Morand, Morann | (MUR-an) | | | M |
| Muadán, Muadhán | (MOO-awn) | derived from muad, "noble, good" | | M |
| Muadnat, Muadhnait | (MOO-a-nit) | fem. form of Muadán | Monait, Mona | F |
| Mugain, Mughain | (MOON) | | | F |
| Mugrón, Mughrón | (moo-RAWN) | perhaps "lad of the seals" | | M |
| Muirecht, Muireacht | (MIR-akt) | | | F |
| Muirchertach, Muircheartach | (MIR-ar-tach) | | Moriarty, Murtagh | M |
| Muirecán, Muireagán | (MIR-a-gawn) | perhaps dim. of muire, "a lord" | | M |
| Muiredach, Muireadhach, Muiríoch | (MIR-ick) | | Merrick | F |
| Muirenn, Muireann | (MIR-an) | "sea-white, sea-fair" | | F |
| Muirgen, Muirghein, Muirín | (mir-EEN) | "born of the sea" | | F |
| Muirgel, Muirgheal, Muiríol | (mir-EEL) | | | F |
| Muirgius, Muirgheas, Muiríos | (MIR-ees) | "sea-strength" | Maurice, Morris | M |
| Muirne | (MIR-nee) | "high-spirited" | | F |
| Munnu, Muna | (MUN-a) | pet form of Fintan | | M |
| Mura | (MUR-a) | pet form of Murchad | | M |
| Murchad, Murchadh | (MUR-a-ka) | | Murrough | M |
| Murchú | (MUR-koo) | "hound of the sea" | | M |