Starting with letter M
| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 41 | MacAulay | Scottish | Son of Olaf. | M | |
| 42 | MacAuliffe | Irish | Son of Olaf. | M | |
| 43 | MacAuslan | Scottish | Son of Absalon. | M | |
| 44 | MacBain | Scottish | Son of Beathan. | M | |
| 45 | MacBeth | Scottish | Son of Beth. | M | |
| 46 | Macbeth | Shakespearean | 'The Tragedy of Macbeth' Thane of Glamis and Cawdor, a general in the King's army, who murders King Duncan and takes his crown. | M | |
| 47 | MacBride | Irish | Son of Bridget 'Bride'. | M | |
| 48 | MacCallum | Scottish | Son of Callum. | M | |
| 49 | MacClennan | Scottish | Son of Finnian's servant. | M | |
| 50 | MacColl | Scottish | Son of Coll. | M | |
| 51 | MacCormack | Irish | Son of Cormac. | M | |
| 52 | MacDhuBh | Scottish | Son of the blackman. | M | |
| 53 | MacDomhnall | Scottish | Son of the world's ruler. | M | |
| 54 | MacDougal | Scottish | Son of Dougal. | M | |
| 55 | Macduff | Shakespearean | 'The Tragedy of Macbeth' Macduff, Thane of Fife, a nobleman of Scotland who finally kills Macbeth. | M | |
| 56 | Mace | English | A mace was a medieval weapon used by knights. | M | |
| 57 | MacElroy | Irish | Son of Elroy. | M | |
| 58 | Macerio | Spanish | Form of Mace which is a medieval weapon used by knights. | M | |
| 59 | MacEwen | Scottish | Son of Ewen. | M | |
| 60 | MacFarlane | Scottish | Son of Farlan. | M | |