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 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. During the 1920s he pursued a variety of occupations. In 1929 he resumed graduate studies that 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.
At the end of the 1930s he held a short-lived academic appointment, but then joined the Nazi Party in 1940. He moved into government service, in 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 Czechoslovakia and Poland, and if successful, Russia itself. Christaller was given special charge of planning occupied Poland, and he did so using his central place theory as an explicit guide. 
After the War he joined the Communist Party and became politically active. In addition, he devoted himself to the geography of tourism. From 1950 forward, his Central Place Theory was used to restructure municipal relationships and boundaries in the Federal Republic of Germany and the system is still in place today.
In 1950 Walter Christaller founded together with Paul Gauss and Emil Meynen 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.
- 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.
- 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.