| Site name | Country | County | Nearest town | Site type | Access | Classification (girth in metres) | View on map |
|---|---|---|---|---|---|---|---|
| Clocaenog | Wales | Denbighshire | Ruthin | churchyard | Yes | Ancient 5m-7m | View On Map |
| Clodock | England | Herefordshire | Abergavenny | garden | No | Notable | View On Map |
| Cloncaird Castle | Scotland | Ayrshire | Ayr | castle | No | Ancient 4m-5m | View On Map |
| Clonfert | Ireland | Co. Galway | Dublin | churchyard | Yes | Notable | View On Map |
| Clonmannon | Ireland | Co. Waterford | Wicklow | estate | No | Ancient 4m-5m | View On Map |
| Clontarf | Ireland | Dublin | Dublin | garden | No | Notable | View On Map |
| Close Walks – Midhurst | England | Sussex - West | Midhurst | planted avenue | Yes | Lost | View On Map |
| Clun | England | Shropshire | Knighton | churchyard | Yes | Ancient 4m-5m, Ancient 5m-7m, Ancient 7m+ | View On Map |
| Clunbury | England | Shropshire | Craven Arms | churchyard | Yes | Ancient 4m-5m | View On Map |
| Clunbury – Twitchen Road | England | Shropshire | Craven Arms | garden | No | Notable | View On Map |
| Clyro | Wales | Powys | Hay-on-Wye | churchyard | Yes | Ancient 4m-5m | View On Map |
| Co Derry – private location | Ireland | Co. Derry | field | No | Ancient 5m-7m | No Map Data | |
| Coates | England | Gloucestershire | Cirencester | churchyard | Yes | Ancient 4m-5m, Notable | View On Map |
| Cobham | England | Surrey | Leatherhead | churchyard | Yes | Lost | View On Map |
| Cobley Wood | England | Hampshire | Whitchurch | woodland | No | Ancient 5m-7m | View On Map |
| Cocking | England | Sussex - West | Midhurst | woodland | No | Ancient 4m-5m | View On Map |
| Coddenham | England | Suffolk | Stowmarket | churchyard | Yes | Notable | View On Map |
| Codford St Mary | England | Wiltshire | Warminster | churchyard | Yes | Notable | View On Map |
| Codsall | England | Staffordshire | Wolverhampton | churchyard | Yes | Ancient 4m-5m, Ancient 5m-7m | View On Map |
| Coed Beddick | Wales | Monmouthshire | Tintern | woodland | Yes | Ancient 4m-5m | View On Map |