| Country: | Wales |
| Official Name: | Isallt Bach |
| Coordinates: | 53.283°N -4.6268°W |
| Cardiff Distance Mi: | 138.7 |
| Cardiff Distance Km: | 223.3 |
| London Distance Mi: | 225.8 |
| London Distance Km: | 363.4 |
| Community Wales: | Trearddur |
| Unitary Wales: | Anglesey |
| Constituency Welsh Assembly: | Ynys Môn |
| Constituency Westminster: | Ynys Môn |
| Post Town: | Holyhead |
| Postcode District: | LL65 |
| Os Grid Reference: | SH 2498 7945 |
Isallt Bach is a hamlet in the community of Trearddur, Anglesey, Wales, which is 138.7 miles (223.3 km) from Cardiff and 225.8 miles (363.4 km) from London.[1]