| Site name | Country | County | Nearest town | Site type | Access | Classification (girth in metres) | View on map |
|---|---|---|---|---|---|---|---|
| Mountfield | England | Sussex - East | Battle | garden | No | Ancient 4m-5m | View On Map |
| Mounton | Wales | Monmouthshire | Chepstow | churchyard | Yes | Ancient 5m-7m | View On Map |
| Mounton/Pwllmeyric | Wales | Monmouthshire | Chepstow | footpath/road | Yes | Notable | View On Map |
| Moy | Ireland | Co. Tyrone | Dungannon | garden | No | Ancient 4m-5m | View On Map |
| Much Birch | England | Herefordshire | Hereford | churchyard | Yes | Ancient 4m-5m, Notable | View On Map |
| Much Cowarne | England | Herefordshire | Hereford | churchyard | Yes | Notable | View On Map |
| Much Dewchurch | England | Herefordshire | Hereford | churchyard | Yes | Ancient 4m-5m | View On Map |
| Much Marcle | England | Herefordshire | Ledbury | churchyard | Yes | Ancient 7m+ | View On Map |
| Much Marcle – Yew Tree House | England | Herefordshire | Ledbury | garden | No | Lost | View On Map |
| Muckross Friary | Ireland | Co. Kerry | Killarney | former religious site | Yes | Notable | View On Map |
| Mugdock Country Park | Scotland | Stirling | Glasgow | historic site | Yes | Ancient 4m-5m | View On Map |
| Mugginton | England | Derbyshire | Derby | churchyard | Yes | Ancient 7m+, Notable | View On Map |
| Mulloch Mor | Ireland | Co. Clare | Gort | cliff | Yes | Notable | View On Map |
| Muncaster | England | Cumbria | churchyard | Yes | Ancient 4m-5m | View On Map | |
| Munsley | England | Herefordshire | Ledbury | churchyard | Yes | Ancient 7m+ | View On Map |
| Munslow | England | Shropshire | Church Stretton | churchyard | Yes | Ancient 5m-7m, Notable | View On Map |
| Munslow Deans | England | Shropshire | Church Stretton | footpath/road | Yes | Ancient 4m-5m, Ancient 5m-7m | View On Map |
| Murthly Castle | Scotland | Perth and Kinross | Perth | castle | No | Ancient 4m-5m | View On Map |
| Mutrécy | France | Calvados - Normandie | Caen | churchyard | Yes | Notable | View On Map |
| Myddelton House – Enfield | England | Greater London | London | garden | Yes | Notable | View On Map |