Prince Wilhelm of Prussia (Wilhelm Friedrich Franz Joseph Christian Olaf; 4 July 1906 – 26 May 1940) was the eldest child of Crown Prince Wilhelm of Germany and Duchess Cecilie of Mecklenburg-Schwerin. At his birth, he was second in line to the German throne and was expected to succeed to the throne after the deaths of his grandfather and father, both of whom, however, outlived him.

Wilhelm was born on 4 July 1906 at the Hohenzollern family's private summer residence, Marmorpalais, or Marble Palace, near Potsdam, where his parents were residing until their own home, Schloss Cecilienhof, could be completed. His father was Crown Prince Wilhelm, the eldest son and heir to the German Emperor, Wilhelm II. His mother was Duchess Cecilie of Mecklenburg-Schwerin. Emperor Franz Joseph of Austria was one of the Prince's godfathers.

The selection of a nanny for Wilhelm and his younger brother, Louis Ferdinand (born in 1907) caused considerable distress within the family.

On his tenth birthday in 1916, Wilhelm was made a lieutenant in the 1st Guards Regiment, and was given the Order of the Black Eagle by his grandfather. Two years later, when he was only twelve, the German monarchy was abolished. Wilhelm and his family remained in Germany, though his grandfather, the former Emperor, went into exile in the Netherlands. The former Crown Prince and his family remained in Potsdam, where Wilhelm and his younger brothers attended the local gymnasium.

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