| Lake King William | |
| Coordinates: | -42.225°N 146.2472°W |
| Type: | Reservoir |
| Basin Countries: | Australia |
| Pushpin Map: | Tasmania |
| Pushpin Map Caption: | Location in Tasmania |
Lake King William is a reservoir on the upper Derwent River in Tasmania, Australia.
Lake King William is created by the Clark Dam, as part of the Upper Derwent hydro scheme.[1] The Cradle Mountain-Lake St Clair National Park, a component of the Tasmanian Wilderness World Heritage Area, has its boundary to the north of the lake shore.