| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 21 | Anghus | Celtic | Exceptionally strong. | M | |
| 22 | Angus | Celtic | Exceptionally strong. | M | |
| 23 | Annan | Celtic | From the stream. | M | |
| 24 | Ansgar | Celtic | Warrior. | M | |
| 25 | Anwell | Celtic | Beloved. | M | |
| 26 | Anwyl | Celtic | Beloved. | M | |
| 27 | Anyon | Celtic | Anvil. | M | |
| 28 | Aod | Celtic | Mythical son of Lyr. | M | |
| 29 | Aodh | Celtic | Fire. | M | |
| 30 | Aodhan | Celtic | Fire. | M | |
| 31 | Aonghus | Celtic | Exceptionally strong. | M | |
| 32 | Ap Owen | Celtic | Son of Owen. | M | |
| 33 | Arawn | Celtic | Mythical king of the Underworld. | M | |
| 34 | Arden | Celtic | Eager; ardent. | M | |
| 35 | Argyle | Celtic | From the land of the Irish. | M | |
| 36 | Arlan | Celtic | Oath. | M | |
| 37 | Arlen | Celtic | Oath. | M | |
| 38 | Arlin | Celtic | Oath. | M | |
| 39 | Arlyn | Celtic | Oath. | M | |
| 40 | Art | Celtic | Strong as a bear. | M | |