Grand Junction Isle is an island in the River Thames on the reach above Molesey Lock at Sunbury-on-Thames, Surrey, England. It is just downstream of Sunbury Court Island. The island contains several weekend chalets and moorings and is connected to the northern bank near Sunbury by a footbridge.
The island takes its name from the Grand Junction Waterworks Company which was one of three companies operating at Hampton Water Works. The company built a water intake on the island to feed the reservoirs nearby. The island was previously known as "Purvis Ait".[1]
| Next island upstream | River Thames | Next island downstream |
| Sunbury Court Island | Grand Junction Isle | Platts Eyot |