A landmass, or land mass, is a large region or area of land that is in one piece and not broken up by oceans. The term is often used to refer to lands surrounded by an ocean or sea, such as a continent or a large island. In the field of geology, a landmass is a defined section of continental crust extending above sea level.
Continents are often thought of as distinct landmasses and may include any islands that are part of the associated continental shelf. When multiple continents form a single contiguous land connection, the connected continents may be viewed as a single landmass. Earth's largest landmasses are (starting with largest):
- Africa-Eurasia (main landmass of the geoscheme region of the same name and its continential parts Africa and Eurasia - or Europe and Asia; the center of Earth's land hemisphere, comprising more than half of Earth's landmass)
- Americas (main landmass of the geo-region of the same name and its continential parts North and South America; comprising most of the landmass of the Western Hemisphere)
- Antarctica (main landmass of the geo-region and continent of the same name)
- Mainland Australia (main landmass of the geo-region Oceania, its sub-region Australasia, the continent Australia and the country Australia)