| Site name | Country | County | Nearest town | Site type | Access | Classification (girth in metres) | View on map |
|---|---|---|---|---|---|---|---|
| Shortgrove House – Newport | England | Essex | Saffron Walden | estate | No | Ancient 5m-7m | View On Map |
| Shottesbrooke Park | England | Berkshire | Maidenhead | churchyard | Yes | Ancient 5m-7m | View On Map |
| Shuckburgh Hall | England | Warwickshire | Daventry | parkland | No | Ancient 5m-7m | View On Map |
| Shugborough | England | Staffordshire | Stafford | parkland | Yes | Notable | View On Map |
| Shute | England | Devon | Axminster | churchyard | Yes | Lost | View On Map |
| Siccaridge Wood – Daneway | England | Gloucestershire | Cirencester | woodland | Yes | Notable | View On Map |
| Sidbury | England | Shropshire | Bridgnorth | churchyard | Yes | Ancient 7m+ | View On Map |
| Siddington | England | Cheshire | Macclesfield | churchyard | Yes | Ancient 4m-5m | View On Map |
| Sidmouth | England | Devon | Exeter | churchyard | Yes | Notable | View On Map |
| Silchester | England | Hampshire | churchyard | Yes | Ancient 4m-5m | View On Map | |
| Silian | Wales | Ceredigion | Lampeter | churchyard | Yes | Ancient 7m+ | View On Map |
| Silver Springs Hotel – Tivoli | Ireland | Co. Cork | Cork | garden | Yes | Ancient 4m-5m | View On Map |
| Silverton | England | Devon | Tiverton | churchyard | Yes | Ancient 7m+ | View On Map |
| Silvington – High Lane | England | Shropshire | Cleobury Mortimer | footpath/road | Yes | Ancient 4m-5m, Ancient 5m-7m, Notable | View On Map |
| Silwood Park | England | Berkshire | Bracknell | parkland | No | Notable | View On Map |
| Simmonscourt Castle | Ireland | Co. Dublin | Dublin | historic site | Yes | Notable | View On Map |
| Sizergh – Holeslack Wood | England | Cumbria | Kendal | woodland | Yes | Ancient 5m-7m, Ancient 7m+, LostNotable | View On Map |
| Skenfrith | Wales | Monmouthshire | Monmouth | churchyard | Yes | Ancient 4m-5m | View On Map |
| Skilgate | England | Somerset | Dulverton | churchyard | Yes | Ancient 4m-5m | View On Map |
| Skipton Castle | England | Yorkshire - North | Skipton | castle | Yes | Notable | View On Map |