- Adur District, West Sussex
- Albourne, Mid Sussex District, West Sussex
- Alciston, Wealden District, East Sussex
- Aldingbourne, Arun District, West Sussex
- Aldrington, City of Brighton and Hove
- Aldwick, Arun District, West Sussex
- Alfoldean Roman Settlement, Slinfold, West Sussex
- Alfriston, Wealden District, East Sussex
- Amberley, Horsham District, West Sussex
- Ambersham
- Anderida or Andredesceaster
- Angmering, Arun District, West Sussex
- Ansty, Mid Sussex District, West Sussex
- Appledram/Apuldram, Chichester District, West Sussex
- Ardingly, Mid Sussex District, West Sussex
- Ardingly: Ardingly College
- Arlington, Wealden District, East Sussex
- Arun District, West Sussex
- Arundel Castle, Arundel, West Sussex
- Arundel, West Sussex
- Ashburnham, Rother District, East Sussex
- Ashdown Forest, East Sussex
- Ashington, Horsham District, West Sussex
- Ashurst, Horsham District, West Sussex
- Avisford, The hundred of
