| Site name | Country | County | Nearest town | Site type | Access | Classification (girth in metres) | View on map |
|---|---|---|---|---|---|---|---|
| Thanington | England | Kent | Canterbury | churchyard | Yes | Ancient 5m-7m | View On Map |
| The Hirsel | Scotland | Scottish Borders | Coldstream | woodland | Yes | Notable | View On Map |
| The Lee | England | Buckinghamshire | Amersham | churchyard | Yes | Ancient 4m-5m | View On Map |
| The Lodge – North Berwick | Scotland | East Lothian | Edinburgh | garden | Yes | Notable | View On Map |
| The Stones, Old Radnor | Wales | Powys | Kington | garden | No | Ancient 4m-5m | View On Map |
| Thenford | England | Northamptonshire | Banbury | No | Ancient 4m-5m | View On Map | |
| Thorley | England | Hertfordshire | Bishop's Stortford | churchyard | Yes | Ancient 5m-7m | View On Map |
| Thornbury | England | Herefordshire | Bromyard | churchyard | Yes | Ancient 4m-5m | View On Map |
| Thorndon Park – Ingrave | England | Essex | Brentwood | parkland | Yes | Notable | View On Map |
| Thorne St Margaret | England | Somerset | Wellington | churchyard | Yes | Notable | View On Map |
| Thornford | England | Dorset | Yeovil | churchyard | Yes | Notable | View On Map |
| Thornton | England | Leicestershire | Leicester | churchyard | Yes | Notable | View On Map |
| Thornton Castle | Scotland | Aberdeenshire | Laurencekirk | garden | No | Ancient 4m-5m | View On Map |
| Thornton Steward | England | Yorkshire - North | Leyburn | field | No | Ancient 4m-5m | View On Map |
| Thornythwaite Fell | England | Cumbria | Keswick | upland | Yes | Ancient 5m-7m | View On Map |
| Thorpe Mandeville | England | Northamptonshire | Banbury | churchyard | Yes | Ancient 5m-7m | View On Map |
| Three Cocks – Aberllynfi | Wales | Powys | SJ11300248 | former religious site | Yes | Ancient 5m-7m | View On Map |
| Throwley | England | Kent | Faversham | churchyard | Yes | Ancient 4m-5m | View On Map |
| Thryft House Farm | England | Yorkshire - South | Sheffield | garden | No | Ancient 5m-7m | View On Map |
| Thurloxton | England | Somerset | Taunton | churchyard | Yes | Ancient 4m-5m | View On Map |