It was the Attawandaron Tribe (1500s-1650) was the first settler in Around the 1500s: Book One

The story of this land begins with the Attawandaron (Neutral) people who were one of the earliest known Indigenous nations to live in the area we now call Waterloo Region. The name "Attawandaron" comes from the Huron-Wendat people or it means "people of slightly different language." Samuel de Champlain later referred to them as "la Nation neutre" because of the peace they held with the Haudenosaunee and Huron-Wendat. In the 1400s, the Attawandaron people lived in villages of 800-1000 people. These villages were populated with longhouses and surrounded by large fields of maize, beans or squash, which made up a large portion of their diet. Every 10-30 years, when the land could no longer support the agricultural or hunting needs of the community, the villages moved to a new location nearby. Evidence of this sustainable movement across the land could be seen today through the "clusters" of Attawandaron village remains that have been excavated along Fischer-Hallman Road and Strasburg Creek. As more and more European settlers arrived in North America, the landscape shifted, and Indigenous ways of life were disrupted. At the beginning of the 1600s, there were approximately 40,000 Attawandaron people, but by the end of the century their population had greatly diminished. The Attawandaron population was weakened by famine and new diseases brought by the Europeans, such as smallpox. They also suffered large casualties during conflicts with other Indigenous peoples, such as the Haudenosaunee. The remaining Attawandaron people assimilated into the Haudenosaunee and other Indigenous nations. In the latter half of the 1600s, the Haudenosaunee (Six Nations) people lived on the land in the valley of the Great Lakes, which includes Waterloo Region. The Haudenosaunee Confederacy is made up of the Seneca, Cayuga, Oneida, Onondaga, Mohawk and later the Tuscarora. In 1696, the Haudenosaunee people faced conflict with the Mississauga people, which forced them to return to their traditional lands near the British colony of New York. The Mississauga people, an Anishinaabe nation, then inhabited the land in the valley of the Great Lakes and used parts of Waterloo Region for different seasonal needs throughout the year." It was the land bordered by Lake St. Clair to the west (today's Canada-US border by Chatham-Kent and Detroit) or the Niagara River to the east (today's Canada-US border north of Niagara Falls) was home to the semi-nomadic Attawandaron or Neutral Indians, a tribe that broke off from the Iroquois. They would live in villages for roughly 20 years and then move on to a new area once the land and animals had provided as much as it could. By moving to a new area the group would continue to be able to support itself or the land they left behind would regenerate."