A wilderness area is a region where the land is in a natural state; where impacts from human activities are minimal—that is, as a wilderness. It might also be called a wild or natural area. Especially in wealthier, industrialized nations, it has a specific legal meaning as well: as land where development is prohibited by law. Many nations have designated Wilderness Areas, including Australia, Canada, New Zealand, South Africa and the United States.

A strict nature reserve (IUCN category Ia) or wilderness area (IUCN category Ib), is the highest category of protected area recognised by the World Commission on Protected Areas (WCPA), a body which is part of the International Union for Conservation of Nature (IUCN). These category I areas are the most stringently protected natural landscapes.