Their historical homelands are in and around present-day Onondaga County, New York, south of Lake Ontario.

Being centrally located, they are considered the "Keepers of the Fire" (Kayečisnakwe’nì·yu[3] in Tuscarora) in the figurative longhouse that shelters the Five Nations.

Although the British promised the security of Haudenosaunee homelands, the 1783 treaty of Paris ceded the territory over to the United States.

[5] The tradition tells that at the time the Seneca nation debated joining the Haudenosaunee based on the Great Peacemaker's teachings, a solar eclipse took place.

[9] When the United States won independence, many Onondaga followed Joseph Brant to Upper Canada, where they were given land by the British Crown at Six Nations.

In the aftermath of the "Sullivan Expedition", following the brutal winter of 1780, there was a massive swarm of periodical cicadas, which emerge from underground every seventeen years.

The sudden arrival of such a large quantity of the insects provided a source of sustenance for the Onondaga people who were experiencing severe food insecurity following the Sullivan campaigns and the subsequent brutal winter.

[14] The culture hero Hyenwatha was an Onondaga Indian and was essential in the early organization of the league.

[14] Handsome Lake, the Seneca half-brother of Cornplanter and author of his eponymous Code, died at Onondaga.

[15] There were also special events such as the Planting Feast which would happen in May or when the Onondaga believed the ground was ready.

[15] The Onondaga's Thanksgiving feast in October closely resembled the Green Corn Dance.

On March 11, 2005, the Onondaga Nation in the town of Onondaga, New York, filed a land rights action in federal court, seeking acknowledgment of title to over 3,000 square miles (7,800 km2) of ancestral lands centering in Syracuse, New York.

They hoped to obtain increased influence over environmental restoration efforts at Onondaga Lake and other EPA Superfund sites in the claimed area.