Carl Ortwin Sauer (December 24, 1889 – July 18, 1975) was an American geographer. Sauer was a professor of geography at the University of California at Berkeley from 1923 until becoming professor emeritus in 1957. He has been called "the dean of American historical geography" and he was instrumental in the early development of the geography graduate school at Berkeley. One of his best known works was Agricultural Origins and Dispersals (1952). In 1927, Carl Sauer wrote the article "Recent Developments in Cultural Geography," which considered how cultural landscapes are made up of "the forms superimposed on the physical landscape."
Sauer, of German ancestry, was born in Warrenton, Missouri and graduated from the University of Chicago with a Ph.D. in 1915.
Carl Sauer's paper "The Morphology of Landscape" was probably the most influential in developing ideas on cultural landscapes and is still cited today. However, Sauer's paper was really about his own vision for the discipline of geography, which was to establish the discipline on a phenomenological basis, rather than being specifically concerned with cultural landscapes. "Every field of knowledge is characterized by its declared preoccupation with a certain group of phenomena,” according to Sauer. Geography was assigned the study of areal knowledge or landscapes or chorology—following the thoughts of Alfred Hettner. “Within each landscape there are phenomena that are not simply there but are either associated or independent of each other.” Sauer saw the geographer’s task as being to discover the areal connection between phenomena. Thus "the task of geography is conceived as the establishment of a critical system which embraces the phenomenology of landscape, in order to grasp in all of its meaning and colour the varied terrestrial scene" A collection of Sauer's letters while doing fieldwork in South America has been published.