Frederick Fiske Warren (2 July 1862 – 2 February 1938) was a successful paper manufacturer, fine arts denizen, 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. He was the son of Samuel Dennis Warren and Susan Cornelia Warren of Beacon Hill, Boston, and the brother to U.S. Attorney Samuel D. Warren and to Edward Perry Warren.
Born in Waltham, Massachusetts, Fiske was raised in a mansion on 67 Mount Vernon Street in Beacon Hill in Boston. As part of a philanthropic and highly educated family, the Warren brothers and sisters all enjoyed tranquil childhoods growing up between the family homes in Boston and Waltham, also known as "Cedar Hill".
On 14 May 1891 he married Gretchen Osgood Warren in Boston. The Osgoods were a well-known Beacon Hill family that claimed a direct genealogical line to Anne Hutchinson and John Quincy Adams. Their country house in Harvard, Massachusetts, was added to the National Register of Historic Places in 1996.