James E. Haff (died 1981) was a twentieth-century American writer and graphic artist who has contributed to the scholarship on L. Frank Baum and Oz. He created Who's Who in Oz: An Appendix (1994), which as its title indicates is an update and extension of Jack Snow's Who's Who in Oz (1954). His article on the Soldier with the Green Whiskers, titled "The Man Nobody Knows," appeared in The Baum Bugle, Vol. 22 No. 3 (Winter 1978). He worked on the canon of John R. Neill, publishing a "Neil Checklist" in 1977 and a "Neill Obituary" in 1981, both in the Bugle.
Haff is particularly noted for his maps of Ozian fantasy locations, as in Ruth Plumly Thompson's Yankee in Oz. He has been called "the cartographer of Oz." Maps that he and Dick Martin prepared for Oz and its surrounding countries are widely reproduced.