Prince Waldemar of Prussia (Joachim Friedrich Ernst Waldemar; 10 February 1868 – 27 March 1879) was the sixth child and youngest son of the German Crown Prince and Crown Princess, later Emperor Frederick III and Empress Victoria.

Prince Waldemar was a grandson of both William I, German Emperor, and Queen Victoria of the United Kingdom.

He was a lively, cheerful boy, boisterous and high-spirited, with a sensible, independent and honest nature.

Less than four months after the deaths of his maternal aunt, Alice, Grand Duchess of Hesse and cousin, Marie, Waldemar became seriously ill with diphtheria and died in Berlin, Germany on 27 March 1879.

He was buried in the royal mausoleum attached to the Friedenskirche at Potsdam, near the main altar and his elder brother Prince Sigismund of Prussia.