Naknek River in the context of Bristol Bay Borough, Alaska

The Yupʼik or Yupiaq (sg & pl) and Yupiit or Yupiat (pl), also Central Alaskan Yupʼik, Central Yupʼik, Alaskan Yupʼik (own name Yupʼik sg Yupiik dual Yupiit pl; Russian: Юпики центральной Аляски), are an Indigenous people of western and southwestern Alaska ranging from southern Norton Sound southwards along the coast of the Bering Sea on the Yukon-Kuskokwim Delta (including living on Nelson and Nunivak Islands) and along the northern coast of Bristol Bay as far east as Nushagak Bay and the northern Alaska Peninsula at Naknek River and Egegik Bay. They are also known as Cupʼik by the Chevak Cupʼik dialect-speaking people of Chevak and Cupʼig for the Nunivak Cupʼig dialect-speaking people of Nunivak Island.

The Yupiit are the most numerous of the various Alaska Native groups and speak the Central Alaskan Yupʼik language, a member of the Eskimo–Aleut family of languages. As of the 2010 U.S. Census, the Yupiit population in the United States numbered over 34,000 people, of whom over 22,000 lived in Alaska. The vast majority of these live in the seventy or so communities in the traditional Yupʼik territory of western and southwestern Alaska. About 10,000 speak the language. The Yupʼik had the greatest number of people who identified with one tribal grouping and no other race (29,000). In that census, nearly half of American Indians and Alaska Natives identified as being of mixed race.

The Yupik (/ˈjuːpɪk/; Russian: Юпикские народы) are a group of Indigenous or Aboriginal peoples of western, southwestern, and southcentral Alaska and the Russian Far East. They are related to the Inuit and Iñupiat. Yupik peoples include the following:

• Alutiiq, or Sugpiaq, of the Alaska Peninsula and coastal and island areas of southcentral Alaska.
• Yupʼik or Central Alaskan Yupʼik of the Yukon–Kuskokwim Delta, the Kuskokwim River, and along the northern coast of Bristol Bay as far east as Nushagak Bay and the northern Alaska Peninsula at Naknek River and Egegik Bay in Alaska.
• Siberian Yupik, including Naukan, Chaplino, and—in a linguistic capacity—the Sirenik of the Russian Far East and St. Lawrence Island in western Alaska.

Bristol Bay (Central Yupik: Iilgayaq, Russian: Залив Бристольский) is the easternmost arm of the Bering Sea, at 57° to 59° North 157° to 162° West in Southwest Alaska. Bristol Bay is 400 km (250 mi) long and 290 km (180 mi) wide at its mouth. A number of rivers flow into the bay, including the Cinder, Egegik, Igushik, Kvichak, Meshik, Nushagak, Naknek, Togiak, and Ugashik.

Upper reaches of Bristol Bay experience some of the highest tides in the world. One such reach, the Nushagak Bay near Dillingham and another near Naknek in Kvichak Bay have tidal extremes in excess of 10 m (30 ft), ranking them — and the area — as eighth highest in the world. Coupled with the extreme number of shoals, sandbars, and shallows, it makes navigation troublesome, especially during the area's frequently strong winds. As the shallowest part of the Bering Sea, Bristol Bay is one of the most dangerous regions for large vessels.

Naknek (Central Yupik: Nakniq) is a census-designated place located in and the borough seat of Bristol Bay Borough in the U.S. state of Alaska. As of the 2020 census, the population of the CDP was 470, down from 544 in 2010.

Naknek is located on the north bank of the Naknek River, close to where the river runs into the Kvichak Bay arm of the northeastern end of Bristol Bay. South Naknek is on the other side of the river.