Canada is the country directly north of the United States along most of the two countries’ shared land border.
The Canada–United States boundary stretches across North America, separating Canada from the contiguous United States to the south. It also divides Alaska from Canada, although Alaska lies northwest of the continental United States rather than directly north of it.
At 8,891 kilometers, the international boundary is commonly described as the world’s longest international border. Much of the boundary follows the 49th parallel, but it also passes through the Great Lakes and other waterways, and it includes sections shaped by historical surveying agreements.
The geographic relationship is slightly more complicated than a simple line on a map. Canada is north of the lower 48 states, but portions of the United States, including Alaska, extend farther north than much of Canada’s populated southern region. Still, for a standard geography quiz asking which country lies north of the U.S. border, Canada is the single canonical answer.