Sir Francis Leopold McClintock was an Irish explorer in the British Royal Navy, known for his discoveries in the Canadian Arctic Archipelago. He confirmed explorer John Rae's controversial report gathered from Inuit sources on the fate of Franklin's lost expedition, the ill-fated Royal Navy undertaking commanded by Sir John Franklin in 1845 attempting to be the first to traverse the Northwest Passage.

Franklin's lost expedition was a failed British voyage of Arctic exploration led by Captain Sir John Franklin that departed England in 1845 aboard two ships, HMS Erebus and HMS Terror, and was assigned to traverse the last unnavigated sections of the Northwest Passage in the Canadian Arctic and to record magnetic data to help determine whether a better understanding could aid navigation. The expedition met with disaster after both ships and their crews, a total of 129 officers and men, became icebound in Victoria Strait near King William Island in what is today the Canadian territory of Nunavut. After being icebound for more than a year Erebus and Terror were abandoned in April 1848, by which point two dozen men, including Franklin, had died. The survivors, now led by Franklin's second-in-command, Francis Crozier, and Erebus's captain, James Fitzjames, set out for the Canadian mainland and disappeared, presumably having perished.