| Abbas Waltham | | Alternative name for the ancient parish of White Waltham |
| Abbots Wittenham | | Alternative name for the ancient parish of Little Wittenham |
| Abingdon | | Municipal and parliamentary borough and market town containing the ancient parishes of St. Helen and St. Nicholas |
| Admiston | | Alternative name for the ancient parish of Aldermaston |
| Aldate, St. | | Parish in the city of Oxford containing places in the county of Berkshire |
| Aldermaston | | Parish and village in the hundred of Theale |
| Aldermaston Wharf | | Settlement on the Kennet & Avon canal, falling within three parishes: Aldermaston, Beenham and Padworth |
| Alderworth | | Alternative name for the parish of Aldworth |
| Aldworth | | Parish and village in the hundred of Compton |
| Allder | | Alternative name for the parish of Aldworth |
| All Hallows | | Part of Wallingford town and parish; abolished as a parish in 1648 |
| Altmore | | Place in the parish of White Waltham |
| Amen Corner | | Hamlet in the parish of Binfield |
| Anviles | | Detached part of Kintbury |
| Appleford | | Chapelry and township in the parish of Sutton Courtney. Listed as an ancient parish in Phillimore's Atlas and Index of Parish Registers. |
| Applehouse Hill | | Named area, in the parish of Hurley, possibly extending into the parish of Bisham |
| Appleton | | Parish and village in the hundred of Ock |
| Arborfield | | Parish and village in the hundred of Sonning |
| Arborfield Cross | | Hamlet in the parish of Arborfield |
| Arborfield Garrison | | British Army garrison established in 1911 as Remount Depot and falling within the parishes of Arborfield & Newlands and Barkham |
| Ardington | | Parish and village in the hundred of Wantage |
| Ardington Wick | | Hamlet in the parish of Ardington |
| Ascot | | Parish, joined to Winkfield, in the hundred of Ripplesmere (1868). Ascot South was formed from the parishes of Ascot Heath and Sunninghill in 1897, while Ascot, later called Ascot Heath, was formed from the parishes of Cranbourne, Sunninghill and Bracknell in 1865. Ascot Heath includes the racecourse |
| Ashampstead | | Parish and village in the hundred of Moreton |
| Ashampstead Green | | Hamlet in the parish of Ashampstead |
| Ashbury | | Parish and village in the hundred of Shrivenham |
| Ashmore Green | | Place in the parish of Thatcham |
| Aston | | Hamlet in the parish of Remenham |
| Aston Tirrold | | Parish in the hundred of Moreton |
| Aston Upthorpe | | Hamlet and chapelry of the parish of Blewbury |
| Avington | | Parish and village in the hundred of Kintbury Eagle |
| Awbury Street | | Tything in the parish of Thatcham |
