The Oneida people (/oʊˈnaɪdə/ ^ⓘ oh-NY-də; autonym: Onʌyoteˀa·ká·, Onyotaʼa:ka, the People of the Standing Stone) are a Native American tribe and First Nations band. They are one of the five founding nations of the Iroquois Confederacy in the area of upstate New York, particularly near the Great Lakes and around Oneida Lake and Oneida County.

The Oneida have two federally recognized tribes in the United States: the Oneida Indian Nation in New York, and the Oneida Nation in and around Green Bay, Wisconsin. In Canada the two Oneida First Nations are both located in Ontario: the Six Nations of the Grand River, and the Oneida Nation of the Thames in Southwold.

The name Oneida is derived from the English pronunciation of Onyota'a:ka, the people's name for themselves. Onyota'a:ka means "People of the Standing Stone". This identity is based on an ancient legend. The Oneida people were being pursued on foot by an enemy tribe. As their enemies chased the Oneida into a clearing within the woodlands, they suddenly disappeared. The enemy could not find them, and so it was said that the Oneida had shapeshifted into the stones that stood in the clearing. As a result, they became known as the People of the Standing Stone.

Older legends have the Oneida people identifying as Latilutakówa, the "Big Tree People", "People of big trees". Not much is written about this. Iroquoian elders would have to be consulted on the oral history of this identification. The association may correspond to Iroquoian concepts of the Tree of Peace and the associated belief system of the people.

Individuals born into the Oneida Nation are identified according to their spirit name, or what may be called an Indian name, their clan, and their family unit within a clan. The people have a matrilineal kinship system, and children are considered to be born into the mother's clan, through which descent and inheritance passes. Each gender, clan, and family unit within a clan has particular duties and responsibilities in the tribe. Clan identities go back to the Creation Story of the Onyota'a:ka peoples. The people identify with three clans: the Wolf, Turtle or Bear clans. Children take their social status from their mother's clan. Because of this, her eldest brother is a significant figure for the children, especially boys. He supervises the boys' passage into adulthood as men.

During the early 17th century, the Oneidas occupied and maintained roughly 6 million acres of land in what is modern day central New York State. Formal boundaries were established in the 1768 Treaty of Fort Stanwix, and again, after September 4, 1784, when the governor of New York, George Clinton, requested from the Oneidas the borders of their land, borders were established in the Treaty of Fort Stanwix (1784).

The Oneida, along with the five other tribes of the Iroquois Confederacy, initially maintained a policy of neutrality in the American Revolution. This policy allowed the Confederacy increased leverage against both sides in the war, because they could threaten to join one side or the other in the event of any provocation. Neutrality quickly crumbled, however. The preponderance of the Mohawks, Senecas, Cayugas, and Onondagas sided with the Loyalists and British. For some time, the Oneidas continued advocating neutrality and attempted to restore consensus among the six tribes of the Confederacy.

But ultimately the Oneida, as well, had to choose a side. Because of their proximity and relations with the rebel communities, most Oneida favored the revolutionaries. In contrast, some of the pro-British tribes were closer to the British stronghold at Fort Niagara. In addition, the Oneida were influenced by the Presbyterian missionary Samuel Kirkland, who had worked among them since 1764. A number of Oneida were baptized as Christians in the decade before the Revolution. Kirkland worked to help them with education and their struggles with alcohol. Through relations with him, many began to form stronger cultural links to the colonists.