Archaeological studies and genetic analyses have indicated a human presence in the northern Yukon region from 24,500 BC, and in southern Ontario from 7500 BC. The Paleo-Indian archaeological sites at Old Crow Flats and Bluefish Caves are two of the oldest sites of human habitation in Canada. The characteristics of Canadian Aboriginal societies included permanent settlements, agriculture, complex societal hierarchies, and trading networks. Some of these cultures had collapsed by the time European explorers arrived in the late 15th and early 16th centuries, and have only been discovered through archaeological investigations.
The aboriginal population is estimated to have been between 200,000 and two million in the late 15th century, with a figure of 500,000 accepted by Canada's Royal Commission on Aboriginal Health. As a consequence of the European colonization, Canada's aboriginal peoples suffered from repeated outbreaks of newly introduced infectious diseases such as influenza, measles, and smallpox (to which they had no natural immunity), resulting in a forty- to eighty-percent population decrease in the centuries after the European arrival. Aboriginal peoples in present-day Canada include the First Nations, Inuit, and Métis. The Métis are a mixed-blood people who originated in the mid-17th century when First Nations and Inuit people married European settlers. In general, the Inuit had more limited interaction with European settlers during the colonization period.
The first known attempt at European colonization began when Norsemen settled briefly at L'Anse aux Meadows in Newfoundland around 1000 AD. No further European exploration occurred until 1497, when Italian seafarer John Cabot explored Canada's Atlantic coast for England. Basque and Portuguese mariners established seasonal whaling and fishing outposts along the Atlantic coast in the early 16th century. In 1534, French