Jan Frederik ("Frits") Staal was a Dutch architect and an important figure in the development of modern architecture in the Netherlands in the first half of the twentieth century.
His work organically developed from the Amsterdam School architecture to the New Objectivity (Neue Sachlichkeit), a development that can be seen in many of his buildings.
He was a lifelong socialist and was also a member of the Communist Party for a short time. Staal was also a board member of the architectural society Architectura et Amicitia for several years. From 1920 to 1930 he was a member of the editorial board of Wendingen.