The 1921 World Hard Court Championships (WHCC) (French: Championnats du Monde de Tennis sur Terre Battue) was the fifth edition of the World Hard Court Championships tennis tournament, considered as the precursor to the French Open, and was held on the clay courts of the Stade Français at the Parc de Saint-Cloud in Paris from 28 May until 5 June 1921. The Championships was organised by the Fédération Française de Tennis, which had recently separated from the L'Union des Sociétés Française de Sports Athlétiques, the organiser of the first four editions.