| Sweet Grass Creek | |
| Source1 Coordinates: | 46.0978°N -110.3344°W |
| Mouth Coordinates: | 45.7861°N -109.7897°W |
| Mouth Coord Ref: | [1] |
| Subdivision Type1: | Country |
| Subdivision Name1: | Park and Sweet Grass County, Montana |
| Source1 Elevation: | 3904feet |
| River System: | Yellowstone River |
Sweet Grass Creek is a tributary of the Yellowstone River, approximately 50 mi (80 km) long, in south central Montana in the United States.
It rises in the Gallatin National Forest, in the Crazy Mountains in eastern Park County. It flows northeast, into Sweet Grass County, then southeast, past Melville, and south, joining the Yellowstone 2 mi (3 km) northwest of Greycliff.
Sweet Grass Creek has also been known as: Otter River.[1]