Warren E. Preece (born April 17, 1921, Norwalk, Connecticut, U.S.—died April 11, 2007, Philadelphia, Pennsylvania) was an American encyclopaedist, general editor of Encyclopædia Britannica in the creation of the 15th edition (1974).
Preece was educated at Dartmouth College (B.A., 1943, Phi Beta Kappa) and, after U.S. Army service during World War II, at Columbia University (M.A., 1947). He worked as a newspaper reporter and copy editor in Connecticut and then taught English for a time before becoming public relations director in the 1956 campaign of U.S. Senator Thomas Dodd (Connecticut). Britannica’s publisher, William Benton, also of Connecticut, hired him in 1957 as secretary to the encyclopaedia’s Board of Editors. Preece subsequently (from 1964) served as the editor of Britannica and was a key figure in the development of the 15th edition, which consists of 30 volumes in three parts. After publication of the new edition, he resigned as editor (1975), though he continued to serve as a member of the Board of Editors (vice-chairman 1975–79). He was coauthor of The Technological Order (1962).