| Altha Lake | |
| Location: | Madera County, California |
| Coordinates: | 37.7125°N -119.1453°W |
| Type: | Lake |
| Pushpin Map: | California |
| Pushpin Map Alt: | Location of lake in California. |
Altha Lake is a lake in the Sierra Nevada in eastern Madera County, California.
It is within the boundaries of the Ansel Adams Wilderness, and in the Sierra National Forest.