See J. Kobalenko, The Horizontal Everest: Extreme Journeys on Ellesmere Island (2002).
Ellesmere Island is part of the Qikiqtaaluk Region of the Canadian territory of Nunavut. Lying within the Canadian Arctic Archipelago it is considered part of the Queen Elizabeth Islands, with Cape Columbia being the most northerly point of land in Canada. It comprises an area of , making it the world's tenth largest island and Canada's third largest island. The Arctic Cordillera mountain system covers much of Ellesmere Island, making it the most mountainous in the Canadian Arctic Archipelago. The Arctic Willow is the only woody species to grow on Ellesmere Island.
As was the case for the Dorset (or Palaeoeskimo) hunters and the pioneering Neoeskimos, the Post-Ruin Island and Late Thule culture Inuit used the Bache Peninsula region extensively both summer and winter until environmental, ecological and possibly social circumstances caused the area to be abandoned. It was the last region in the Canadian High Arctic to be depopulated during the "Little Ice Age", attesting to its general economic importance as part of the Smith Sound culture sphere of which it was occasionally a part and sometimes the principal settlement component.
Vikings, likely from the Greenland colonies, reached Ellesmere Island, Skraeling Island and Ruin Island during hunting expeditions and trading with the Inuit groups. Unusual structures on Bache peninsula may be the remains of a late-period Dorset stone longhouse.
The first European to sight the island after the height of the "Little Ice Age" was William Baffin, in 1616; said "Age" lasted until roughly 1850. Ellesmere Island was named in 1852 by Edward Inglefield's expedition after Francis Egerton, 1st Earl of Ellesmere. The American expedition led by Adolphus Greely in 1881 crossed the island from east to west. The Greely expedition found fossil forests on Ellesmere Island in the late 1880s. Stenkul Fiord was first explored in 1902 by Per Schei, a member of Otto Sverdrup's 2nd Norwegian Polar Expedition.
The Ellesmere Ice Shelf was documented by the British Arctic Expedition of 1875-76, in which Lieutenant Pelham Aldrich's party went from Cape Sheridan west to Cape Alert including the Ward Hunt Ice Shelf. In 1906 Robert Peary led an expedition in northern Ellesmere Island, from Cape Sheridan along the coast to the western side of Nansen Sound (93°W). During Peary's expedition, the Ice Shelf was continuous; a modern estimate is that it covered .
In July 2007, a study noted the disappearance of habitat for waterfowl, invertebrates, and algae on Ellesmere Island. According to John P. Smol of Queen's University in Kingston, Ontario, and Marianne S. V. Douglas of the University of Alberta in Edmonton, warming conditions and evaporation have caused low water levels changes in the chemistry of ponds and wetlands in the area. The researchers noted that "In the 1980s they often needed to wear hip waders to make their way to the ponds...while by 2006 the same areas were dry enough to burn.
The breakup of the Ellesmere Ice Shelves has continued in the 21st century: the Ward Ice Shelf experienced a major breakup during summer 2002; the Ayles Ice Shelf calved entirely on August 13, 2005; the largest breakoff of the ice shelf in 25 years, it may pose a threat to the oil industry in the Beaufort Sea. The piece is . In April 2008, it was discovered that the Ward Hunt shelf was fractured into dozens of deep, multi-faceted cracks and in September 2008 the Markham shelf (50 sq km / 20 square miles) completely broke off to become floating sea-ice.
In 2006, University of Chicago paleontologist Neil H. Shubin reported the discovery of the fossil of a Paleozoic (ca. 375 Ma) fish, named Tiktaalik roseae, in the former stream beds of Ellesmere Island. The fossil exhibits many characteristics of fish, but also indicates a transitional creature that may be a predecessor of amphibians, reptiles, dinosaurs, mammals, and eventually humans.
Canadian Forces Station (CFS) Alert is the northernmost settlement in the world. With the end of the Cold War and the advent of new technologies allowing for remote interpretation of data, the overwintering population has been reduced to 50.
Eureka, which is the second northernmost settlement in the world, consists of three areas, "Eureka Airport" which includes "Fort Eureka" (the quarters for military personnel maintaining the island's communications equipment), the Environment Canada Weather Station and the Polar Environmental Atmospheric Research Laboratory (PEARL), formally the Arctic Stratospheric Ozone (AStrO) Observatory.