| Alder Creek | |
| Name Other: | Tributary to Prosser Creek |
| Image Alt: | Alder Creek |
| Map Size: | 300 |
| Pushpin Map: | USA California#USA |
| Pushpin Map Size: | 300 |
| Pushpin Map Caption: | Location of Alder Creek mouth |
| Pushpin Map Alt: | Map of Alder Creek mouth location |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | California |
| Subdivision Type3: | County |
| Subdivision Name3: | Nevada |
| Length: | 8.89miles[1] |
| Discharge1 Location: | Prosser Creek |
| Discharge1 Avg: | 15.55cuft/s at mouth with Prosser Creek[2] |
| Source1: | Negro Canyon divide |
| Source1 Location: | Donner Ridge |
| Source1 Coordinates: | 39.3831°N -120.6261°W[3] |
| Source1 Elevation: | 7490feet[4] |
| Mouth: | Prosser Creek |
| Mouth Location: | Prosser Creek Reservoir, about 2 miles north-northwest of Polaris, California |
| Mouth Coordinates: | 39.3775°N -120.645°W |
| Mouth Elevation: | 5741feet[5] |
| Progression: | Prosser Creek → Truckee River → Pyramid Lake |
| River System: | Truckee River |
| Tributaries Left: | unnamed tributaries |
| Tributaries Right: | unnamed tributaries |
| Bridges: | Skislope Way, Snowpeak Way, Fjord Road, Schussing Way, Alder Creek Road, CA 89 |
Alder Creek is a perennial stream in Nevada County, California, mostly within the town of Truckee. Its source region near Donner Ridge is west of town, and its mouth at Prosser Creek Reservoir is north of town. It flows to the Truckee River via Prosser Creek.
The Donner Party camped in Alder Creek Valley when stopped by snow in November, 1846. There is a memorial to them off California route 89 just north of the creek.