Sir George Simpson (c. 1792 – 7 September 1860) was a Scottish explorer and colonial governor of the Hudson's Bay Company (HBC) during the period of its greatest power. From 1820 to 1860, he was in practice, if not in law, the British viceroy for the whole of Rupert's Land, an enormous territory of 3.9 million square kilometres (1.5 million square miles) corresponding to nearly forty per cent of modern-day Canada.

His efficient administration of the west was a precondition for the confederation of western and eastern Canada, which later created the Dominion of Canada. He was noted for his grasp of administrative detail and his physical stamina in traveling through the wilderness. Excepting voyageurs and their Siberian equivalents, few men have spent as much time travelling in the wilderness.

Simpson was also the first person known to have "circumnavigated" the world by land, and became the most powerful man of the North American fur trade during his lifetime.

Born out of wedlock to a solicitor in Dingwall, Scotland, Simpson was raised primarily by an aunt, and received a basic education at the local parish school. As a teenager, he was sent to apprentice as a clerk at an uncle's sugar brokerage in London, where he learned the intricacies of international trade, and demonstrated his clerical and managerial proficiency. He first came to the attention of the Hudson's Bay Company's management when his uncle's firm merged with that of Andrew Colvile-Wedderburn, a member of the Hudson Bay Company's board of directors.

In 1820, despite his lack of experience in the North American fur trade, Simpson was appointed as the company's North American governor-in-chief locum tenens. He was chosen as an outsider to replace the existing North American governor, William Williams, should he be arrested by the North West Company (NWC), with whom the HBC was in conflict. Simpson emigrated to North America that year, where he was placed in charge of the Athabasca Department. In 1821, upon the amalgamation of the HBC and NWC, he was appointed as the governor of the newly established Northern Department of the HBC, whose territory extended from Fort Albany to the Pacific coast. In 1826 he assumed authority over the Southern Department, making him the sole governor of the entirety of the Hudson's Bay Company's territory in North America.

His governorship was defined by the reorganization of the fur trade, a new focus on the Pacific coast, and his frequent cross-continental trips during which he would visit the forts within his domain. He made two trips to the Columbia River, in 1824 and 1827, and in 1841 made an overland journey around the world. He held the role of governor until his death in 1860.

George Simpson was born c. 1792 in Dingwall, Ross-Shire, Scotland. He was the illegitimate son of George Simpson Sr, a solicitor from the nearby village of Avoch. George Simpson Sr was related through marriage to Alexander Mackenzie, and was a descendant of George Mackenzie, 2nd Earl of Seaforth, and Duncan Forbes of Culloden. Having originally been sent to Dingwall for his legal apprenticeship, Simpson Sr eventually served as a solicitor for the Sheriff's Court. In 1786, when his father Thomas Simpson died, Simpson Sr was joined in Dingwall by his mother Isobel, and his younger siblings Jean, Mary, Geddes and Duncan.

Simpson was primarily raised by his aunt Mary, who served as his foster mother particularly after his father left to work in the nearby town of Ullapool. He received about eight or nine years of education at the parish school, where he was taught reading, writing, arithmetic and geography. He studied alongside Æmelius Simpson, the illegitimate son of the schoolmaster Alexander Simpson, who would later also work for the Hudson's Bay Company. Towards the end of his education, he tutored Duncan Finlayson, who would remain a close friend. In 1807, the schoolmaster Alexander Simpson married George's aunt Mary, and a year later she gave birth to Thomas Simpson, George's first cousin, who he would later employ for the HBC.