The category of natural resources is commonly taken to comprise anything – whether matter or energy – which is potentially useful to human beings, but which was not created by human beings. All of us require some land to stand upon, air to breathe, and water to drink, and in that sense natural resources are key to human survival. Moreover – though doing so is not always easy – individuals or communities lucky enough to command larger than average supplies of valuable resources such as oil or gold may manage to convert their good fortune into great wealth. Because the ownership of natural resources can be so consequential for people's well‐being, philosophers have argued for centuries about just how the pattern of resource ownership ought, morally speaking, to be constrained. This entry aims to provide an overview of debates about the justice or injustice of patterns of resource ownership. First, we consider ongoing debates about the circumstances in which individual agents can come to be the owners of the world's natural resources. Second, we consider the way in which arguments about natural resource ownership have come to play an important role in more recent debates about the territorial rights of states.