Duncan McGillivray (1770 – April 9, 1808), born in Inverness-shire, Scotland, was an explorer and fur trader who accompanied David Thompson on explorations of Rupert's Land and the Canadian Rockies. In 1800, they reached what is now Banff National Park. By 1801, McGillivray was suffering from rheumatism, and returned to Montreal.
In 1808 David Thompson gave what is now called the Kootenay River the name McGillivray's River, in honour of William and Duncan McGillivray. Duncan also loved the outdoors, and once took home and dissected a mountain goat.
Duncan was an older brother to Simon McGillivray and both were involved in McTavish, McGillivrays and Company with their brother William.