Prisoners came from all over Europe and the Soviet Union—Jews, Poles and other Slavs, the mentally ill and physically disabled, political prisoners, Romani people, Freemasons, and prisoners of war. There were also ordinary criminals and sexual "deviants". All prisoners worked primarily as forced labor in local armaments factories. The insufficient food and poor conditions, as well as deliberate executions, led to 56,545 deaths at Buchenwald of the 280,000 prisoners who passed through the camp and its 139 subcamps. The camp gained notoriety when it was liberated by the United States Army in April 1945; Allied commander Dwight D. Eisenhower visited one of its subcamps.

From August 1945 to March 1950, the camp was used by the Soviet occupation authorities as an internment camp, NKVD special camp Nr. 2, where 28,455 prisoners were held and 7,113 of whom died. Today the remains of Buchenwald serve as a memorial and permanent exhibition and museum.

The Schutzstaffel (SS) established Buchenwald concentration camp at the beginning of July 1937. The camp was to be named Ettersberg, after the hill in Thuringia upon whose north slope the camp was established. The proposed name was deemed inappropriate, because it carried associations with several important figures in German culture, especially Enlightenment writer Johann Wolfgang von Goethe. Instead the camp was to be named Buchenwald, in reference to the beech forest in the area. However, Holocaust researcher James E. Young wrote that SS leader chose the site of the camp precisely to erase the cultural legacy of the area. After the area of the camp was cleared of trees, only one large oak remained, supposedly one of Goethe's Oaks.

On the main gate, the motto Jedem das Seine (English: "To each his own"), was inscribed. The SS interpreted this to mean the "master race" had a right to humiliate and destroy others. It was designed by Buchenwald prisoner and Bauhaus architect Franz Ehrlich, who used a Bauhaus typeface for it, eventhough Bauhaus was seen as degenerate art by the National Socialists and was prohibited. This defiance however went unnoticed by the SS.

The camp, designed to hold 8,000 prisoners, was intended to replace several smaller concentration camps nearby, including Bad Sulza [de], Sachsenburg, and Lichtenburg. Compared to these camps, Buchenwald had a greater potential to profit the SS because the nearby clay deposits could be made into bricks by the forced labor of prisoners. The first prisoners arrived on 15 July 1937, and had to clear the area of trees and build the camp's structures. By September, the population had risen to 2,400 following transfers from Bad Sulza, Sachsenburg, and Lichtenburg.