| Niukluk River | |
| Map Size: | 300 |
| Pushpin Map: | USA Alaska |
| Pushpin Map Size: | 300 |
| Pushpin Map Caption: | Location of the mouth of the Niukluk River in Alaska |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Alaska |
| Subdivision Type4: | District |
| Subdivision Name4: | Nome Census Area |
| Length: | 52miles[1] |
| Discharge1 Location: | Council, Alaska |
| Discharge1 Max: | 16000cuft/s[2] |
| Source1: | Bendeleben Mountains of the Seward Peninsula |
| Source1 Location: | 5miles northeast of Mount Bendeleben |
| Source1 Coordinates: | 65.2286°N -163.8483°W |
| Source1 Elevation: | 2780feet[3] |
| Mouth: | Fish River |
| Mouth Location: | 34miles northeast of Solomon |
| Mouth Coordinates: | 65.2286°N -163.8483°W[4] |
| Basin Size: | 707sqmi at Council, Alaska |
Niukluk River is a waterway in the U.S. state of Alaska. It rises in the Bendeleben Mountains and, after flowing across a broad valley lowland for about 15miles, enters a narrower valley, in which it flows for about 20miles. Below the mouth of Melsing Creek, the valley broadens out and merges with that of Fish River, to which the Niukluk is a tributary. It receives many tributaries, of which the Koksuktapaga, joining it from the south, is the largest. In Niukluk River itself, gold was found at its head, though most abundant below the mouth of American Creek. Just below the mouth of Ophir Creek, a little gold has been rocked out on the bars. The broad gravel flood plain in this part of the basin is said to be auriferous. Below the mouth of Ophir Creek the river has cut a small rock canyon 50feet below an old valley floor, leaving broad benches on either side. These benches are sheeted over by a few feet of gravel.[5]