A landmass, or land mass, is a large region or area of land that is in one piece and not noticeably 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):

Continental landmasses are not usually classified as islands despite being completely surrounded by water. However, because the definition of continent varies between geographers, the Americas are sometimes defined as two separate continents while mainland Australia is sometimes defined as an island as well as a continent. Nevertheless, for the purposes of this list, mainland Australia along with the other major landmasses have been listed as continental landmasses for comparison. The figures are approximations and are for the four major continental landmasses only.