Walter Christaller (April 21, 1893 – March 9, 1969), was a German geographer whose principal contribution to the discipline is Central Place Theory, first published in 1933. This groundbreaking theory was the foundation of the study of cities as systems of cities, rather than simple hierarchies or single entities.
Walter Christaller was born to Erdmann Gottreich and Helene Christaller, an author of Christian-themed children's novels at Berneck (today part of Altensteig in Germany. His paternal grandfather Johann Gottlieb Christaller was a linguist and a Christian missionary in West Africa.
Before 1914, Christaller began studies in philosophy and political economics and subsequently served in the German Army during World War I. He was homeschooled and educated at the Universities of Heidelberg and Munich. In the 1920s, he pursued a variety of occupations. In 1929, he resumed graduate studies, which led to his famous dissertation on Central Place Theory, which he published as the Die zentralen Orte in Süddeutschland (The Central Places in Southern Germany), in 1933.
In the late 1930s, he held a short-lived academic appointment at the University of Freiburg-in-Breisgau. He was never a Nazi and was even noticed for some brawls with Nazi students. He moved into government service, for Himmler's SS-Planning and Soil Office, during the Second World War. Christaller's task was to draw up plans for reconfiguring the economic geography of Germany's eastern conquests (Generalplan Ost), primarily in Czechoslovakia and Poland but also, if successful, Russia itself. Christaller was given special charge of planning occupied Poland, and he did so by using his central place theory as an explicit guide. 
After the war, he joined the Communist Party of Germany and became politically active. In addition, he devoted himself to the geography of tourism. Since 1950, his Central Place Theory has been used to restructure municipal relationships and boundaries in the Federal Republic of Germany, and the system is still in place today.
In 1950, Christaller, together with Paul Gauss and Emil Meynen, founded the German Association of Applied Geography (DVAG). The Walter Christaller Award for Applied Geography is named after him.
- Christaller, Walter (1933): Die zentralen Orte in Süddeutschland. Gustav Fischer, Jena.
- "Walter Christaller". NNDB. Retrieved 21 August 2012.
- Grunsky F. Nachruf auf Erdmann Gottreich Christaller, 1922.
- Bunge W (1977) “Walter Christaller was not a Fascist”, Ontario Geography, p.80 sqq. ; Hottes R (1982) “W Christaller : ein Überblick über Leben und Werk.” Geographisches Taschenbuch, Wiesbaden pp 59-69.
- Rössler, Mechtild (1989): Applied geography and area research in Nazi society: central place theory and planning, 1933-1945. Environment and Planning D: Society and Space 7, 419-431; Trevor Barnes & Claudio Minca (2013), Nazi Spatial Theory: The Dark Geographies of Carl Schmitt and Walter Christaller. Annals of the Association of American Geographers 103 (3), 669–687. ; - Fahlbusch, M, M Rössler und D Siegrist (1989) “Geographie und Nazionalsozialismus”, Urbs et Regio, 51, kasseler Schriften zur Geographie u. Plannung. ; - Marchand B (1999) “Nazionalsozialismus und Grossstadtfeindschaft”, Die Alte Stadt, 1/99, S39-50. ; - Müller R-D (1991)Hitlers Ostkrieg und die deutsche Siedlungspolitik, Fischer Vlg, Frankfurt am Main. ; - Wasser B (1993) Himmlers Raumplanung im Osten, Der Generalplan Ost in Polen, Birkhaüser Verlag, Basel, Schweiz, 347 S.
- Wardenga, Ute / Henniges, Norman / Brogiato, Heinz Peter und Schelhaas, Bruno: Der Verband deutscher Berufsgeographen. Eine sozialgeschichtliche Studie zur Frühphase des DVAG. (= forum ifl 16), Leipzig 2011.