Cuius est solum, eius est usque ad coelum et ad inferos is a principle of property law, stating that property holders have rights not only to the plot of land itself, but also the air above and the ground below. The principle is often referred to in its abbreviated form as the ad coelum doctrine.

In real estate, air rights are the property interest in the "space" above the Earth's surface. Generally speaking, owning or renting land or a building includes the right to use and build in the space above the land without interference by others.