The Eek River is a 108 mi tributary of the Kuskokwim River in the U.S. state of Alaska. It is south of the Kwethluk River and north of the Kanektok River, which also drain into the Kuskokwim or Kuskokwim Bay on the Bering Sea. Beginning at a small lake near Mount Oratia in the Togiak National Wildlife Refuge, the Eek River flows generally northwest into the Yukon Delta National Wildlife Refuge to meet the larger river near Eek Island in western Alaska. The Eek River supports large populations of pink salmon and Arctic char.