Wilhelmplatz was a square in the Mitte district of Berlin, Germany at the corner of Wilhelmstrasse and Voßstraße. The square also gave its name to a Berlin U-Bahn station which has since been renamed Mohrenstraße. A number of notable buildings were constructed around the square, including the old Reich Chancellery (former Palais Schulenburg), the building of the Ministry of Finance and the Kaiserhof grand hotel built in 1875.
The square was originally laid out in 1721 over the course of the Friedrichstadt expansion and obtained the name Wilhelmplatz in 1749, after King Frederick William I of Prussia. Engineer and chairman of the state building commission Christian Reinhold von Derschau led the project. He was advised by the King's senior and court building directors, Johann Phillipp Gerlach and Johann Friedrich Grael, respectively, who were in charge of the architectural design. Under their influence, the building commission decided on mandatory, narrowly defined guidelines so that the city would give off a harmonious, integrated feel.
Initially, the plan was to lay out the streets in a traditional grid formation. Yet, from 1732 onward, plans focused themselves around three primary North-South throughways that each radiated from the same circular public space, known as the Rondell (today: Mehringplatz). These major streets would later come to be known as Wilhelmstraße, Friedrichstraße and Lindenstraße. According to a royal patent from July 29, 1734, the location of a large square on Wilhelmstraße was also among the construction projects discussed.
In 1737, for the first time, a Plan of the Royal Capital of Berlin demarcates a public square located in the northern third of the street (as it was drawn until the 19th century) opening up from its eastern side. The square came to be known as Wilhelms-Markt, a name it carried until 1749, when it was christened Wilhelmsplatz. The origin of its name is the Prussian "Soldier King" Frederick William I, who had an especially heavy influence on the architecture and expansion of the northern part of Wilhelmstraße.