The word Iroquois is thought to be a French derivation of the Algonkian word ireohkwa meaning "real adders," or real snakes. The word Iroquois today refers to the Six Nations: Cayuga, Mohawk, Oneida, Onondaga, Seneca, and Tuscarora. Today, the Iroquois usually call themselves Haudenosaunee, meaning "People of the Longhouse."

The center of Iroquois territory extended throughout Western, Central, and Northern New York State, northern Pennsylvania, northern Ohio, eastern Michigan, and southern Ontario and Quebec.