| Lock Name: | Hertford Lock |
| Waterway: | River Lee Navigation |
| County: | Hertfordshire |
| Operation: | Manual |
| Maint: | Canal & River Trust |
| Length: | 85feet |
| Width: | 16feet |
| Fall: | 7feet |
| Enda: | Bow Creek |
| Distenda: | 26.3miles |
| Endb: | Hertford Castle Weir |
| Distendb: | 0.8miles |
| Coordinates: | 51.8038°N -0.0667°W |
Hertford Lock (No1) is a lock situated on the River Lea on the eastern side of Hartham Common, Hertford in the English county of Hertfordshire. It is owned and managed by Canal & River Trust and is the first lock of the River Lee Navigation.
The lock is located on the River Lee Navigation towpath which forms part of the Lea Valley Walk