| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 41 | Allene | Celtic | Fair, good-looking. Feminine of Allen or variant of Helen. | F | |
| 42 | Allie | Celtic | Diminutive of Alan: Harmony, stone, or noble. Also fair, handsome. Originally a saint's name, it was reintroduced to Britain during the Norman Conquest, remained popular throughout the Middle Ages, and was revived in the 19th century. | M | |
| 43 | Ally | Celtic | Diminutive of Alan: Harmony, stone, or noble. Also fair, handsome. Originally a saint's name, it was reintroduced to Britain during the Norman Conquest, remained popular throughout the Middle Ages, and was revived in the 19th century. | M | |
| 44 | Allyn | Celtic | Handsome. | M | |
| 45 | Alma | Celtic | Good. | F | |
| 46 | Alun | Celtic | Harmony, stone, or noble. Also fair, handsome. Originally a saint's name, it was reintroduced to Britain during the Norman Conquest, remained popular throughout the Middle Ages, and was revived in the 19th century. | M | |
| 47 | Alys | Celtic | Noble. | F | |
| 48 | Anant | Celtic | From the stream. | M | |
| 49 | Andraste | Celtic | Victory. | F | |
| 50 | Anghus | Celtic | Exceptionally strong. | M | |
| 51 | Angus | Celtic | Exceptionally strong. | M | |
| 52 | Annan | Celtic | From the stream. | M | |
| 53 | Annwfn | Celtic | Mythical name of The Otherworld. | F | |
| 54 | Annwn | Celtic | Mythical name of The Otherworld. | F | |
| 55 | Ansgar | Celtic | Warrior. | M | |
| 56 | Anwell | Celtic | Beloved. | M | |
| 57 | Anwyl | Celtic | Beloved. | M | |
| 58 | Anyon | Celtic | Anvil. | M | |
| 59 | Aod | Celtic | Mythical son of Lyr. | M | |
| 60 | Aodh | Celtic | Fire. | M | |