| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 521 | Malcolm | Gaelic | Servant/disciple of Columba. Famous Bearers: Conductor Sir Malcolm Sargent and U.S. black militant Malcolm X (Malcolm Little). | M | |
| 522 | Malise | Gaelic | Servant of Jesus. | M | |
| 523 | Maloney | Gaelic | Devoted to God. | M | |
| 524 | Malvin | Gaelic | Polished chief. | M | |
| 525 | Mannis | Gaelic | Great. | M | |
| 526 | Manus | Gaelic | Great. | M | |
| 527 | Maoldhomhnaigh | Gaelic | Devoted to God. | M | |
| 528 | Maolmin | Gaelic | Polished chief. | M | |
| 529 | Maoltuile | Gaelic | Quiet. | M | |
| 530 | Marcus | Gaelic | Hammer. | M | |
| 531 | Martainn | Gaelic | Warlike. | M | |
| 532 | Maspann Bhaillidh | Gaelic | Son of the steward. | M | |
| 533 | Mayo | Gaelic | Lives near the yew trees. | M | |
| 534 | Micheal | Gaelic | Form of Michael 'Who is like God?'. | M | |
| 535 | Micheil | Gaelic | Gaelic form of Michael. | M | |
| 536 | Monroe | Gaelic | From the red swamp. | M | |
| 537 | Morfinn | Gaelic | Pale. | M | |
| 538 | Morvan | Gaelic | Pale. | M | |
| 539 | Morven | Gaelic | Pale. | M | |
| 540 | Morvin | Gaelic | Pale. | M | |