Sir Alexander Mackenzie (1764 – 12 March 1820) was a Scottish-Canadian explorer and fur trader known for accomplishing the first crossing of North America north of Mexico by a European in 1793. The Mackenzie River and Mount Sir Alexander are named after him.
As a leading member of the North West Company, he aspired to extend the Company's operations into western Canada and sell furs gained from there in China. His ambitions competed with the monopoly positions of both the Hudson's Bay Company and the East India Company.