| Astlabor | Old English, possibly meaning 'east labor' or 'eastern worker' |
| Aswine | Friend of the Gods |
| Athelhard | Old English, meaning 'noble hard' or 'noble strong' |
| Athelheah | Old English, meaning 'noble brightness' or 'noble light' |
| Athelmod | Old English, meaning 'noble moderation' or 'noble balance' |
| Oswall | Rule of God; Divine Power |
| Oswinus | Latin origin, meaning 'divine friend' or 'friend of God' |
| Oswold | Rule of God; Divine Power |
| Oswudu | Old English, meaning 'divine wood' or 'wood of God' |
| Oswuff | Old English, possibly meaning 'divine wolf' or 'wolf of God' |
| Oswulf | Means divine wolf in English. |
| Osyth | Old English, meaning 'divine strength' or 'strong in God' |
| Otta | Means wealthy or prosperous. |
| Ottewell | Old English, meaning 'brave well' or 'strong well' |
| Otuel | Old English, meaning 'brave people' or 'strong tribe' |
| Oudoceus | Latin origin, meaning 'good news' or 'joyful tidings' |
| Ouein | Greek origin, meaning 'good' or 'beautiful' |
| Oughtred | Old English, meaning 'brave counsel' or 'strong advice' |
| Owaine | Youth; Lamb; Yahweh is Gracious |
| Oxforde | Place name origin, meaning 'ox ford' or 'ford of oxen' |
| Ozwell | Old English, possibly meaning 'divine well' or 'well of God' |
| Athruis | God or divine being |
| Atrit | From the land or territory |
| Attwood | Dweller by the wood |
| Atwoode | From the wood or forest |
| Aub | Supernaturally Powerful; Elf Ruler |
| Aubelet | Bright or shining light |
| Auberi | Bright or shining light |
| Aubertin | Bright or shining light |
| Aubinnet | Bright or shining light |
| Aubri | Supernaturally Powerful; Elf Ruler |
| Audy | Noble and strong power |
| Auger | Strong or powerful |
| Auicatus | Wise or intelligent |
| Auner | One who makes ovens |
| Autti | Derived from Finnish, meaning 'little father' or 'young father' |
| Auveray | From the Old French for 'from the river' |
| Auvrai | From the Old French for 'from the place' |
| Avalloch | Stronghold or fortified place |
| Avarloch | Stronghold or fortified place |