Frederick Fiske Warren (2 July 1862 – 2 February 1938) was a successful paper manufacturer, fine arts doyen, United States tennis champion of 1893, and major supporter of Henry George's single tax system which he helped develop in Harvard, Massachusetts, United States, in the 1930s. Fiske Warren established Georgist single-tax colonies and a social experiment in Andorra to disprove Malthus's population theory.