Sm-Sn
- Smith River - California
- Smith River - Montana
- Smith River - New Hampshire
- Smith River - Oregon
- Smith River - Virginia, North Carolina
- Smoky Hill River - Colorado, Kansas
- Smyrna River - Delaware
- Snake River - Wyoming, Idaho, Oregon, Washington
- Snake River - Colorado
- Snake River - Minnesota (Elk River tributary)
- Snake River - Minnesota (Red River tributary)
- Snake River - Minnesota (St. Croix River tributary)
- Snake River - Nebraska
- Snohomish River - Washington
- Snoqualmie River - Washington
Read more about this topic: List Of Rivers Of The United States: S