| Hamma Hamma River | |
| Map Size: | 300 |
| Pushpin Map: | USA Washington |
| Pushpin Map Size: | 300 |
| Pushpin Map Caption: | Location of the mouth of the Hamma Hamma River in Washington |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Washington |
| Subdivision Type4: | County |
| Subdivision Name4: | Mason |
| Discharge1 Location: | near Eldon[1] |
| Discharge1 Min: | 39cuft/s |
| Discharge1 Avg: | 364.4cuft/s[2] |
| Discharge1 Max: | 6010cuft/s |
| Source1: | Olympic Mountains |
| Source1 Coordinates: | 47.5669°N -123.3181°W |
| Mouth: | Hood Canal |
| Mouth Coordinates: | 47.5456°N -123.0417°W |
The Hamma Hamma River is a river on the Olympic Peninsula in the U.S. state of Washington. It rises near Mount Washington in the Olympic Mountains within the Olympic National Park and drains to Hood Canal and thence to the Pacific Ocean.
The name Hamma Hamma comes from a Twana village once located at the river's mouth and called Hab'hab, referring to a reed that grows along the river's banks.[3]