| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 1 | Abboid | Gaelic | Abbey father. | M | |
| 2 | Adair | Gaelic | From the oak tree ford. | M | |
| 3 | Adhamh | Gaelic | Gaelic form of Adam. | M | |
| 4 | Aherin | Gaelic | Owns many horses. | M | |
| 5 | Ahern | Gaelic | Owns many horses. | M | |
| 6 | Aherne | Gaelic | Owns many horses. | M | |
| 7 | Aidan | Gaelic | Little fire, ardent. Aidan was popular in Ireland in the 7th century after the famous Irish monk Aidan, and was revived in the early 19th century. | M | |
| 8 | Aiden | Gaelic | Fiery. | M | |
| 9 | Ailean | Gaelic | Handsome. | M | |
| 10 | Ailen | Gaelic | Handsome. | M | |
| 11 | Ailin | Gaelic | Handsome. | M | |
| 12 | Aindreas | Gaelic | Manly. | M | |
| 13 | Airdsgainne | Gaelic | From the height of the cliff. | M | |
| 14 | Airleas | Gaelic | Pledge. | M | |
| 15 | Al | Gaelic | Diminutive of Alistair: A Scottish Gaelic variant of Alexander from the Greek meaning defender of man. | M | |
| 16 | Alai | Gaelic | Defender of man. | M | |
| 17 | Alasdair | Gaelic | A Scottish Gaelic variant of Alexander from the Greek meaning defender of man. | M | |
| 18 | Alastair | Gaelic | Variant of Alexander defender of mankind. | M | |
| 19 | Alaster | Gaelic | Defender of man. | M | |
| 20 | Alistair | Gaelic | A Scottish Gaelic variant of Alexander from the Greek meaning defender of man. | M | |