The Fitz Hugh Ludlow Memorial Library is a library of psychoactive drug-related literature created in 1970 by Michael Horowitz, Cynthia Palmer, William Dailey, and Robert Barker, who merged their private libraries. It is the largest such library in the world and was based in San Francisco, California; the Ludlow Library is now part of the Ludlow Santo Domingo Library sarl, in Geneva, Switzerland. It is named for Fitz Hugh Ludlow, author of the first full-length work of drug literature written by an American, The Hasheesh Eater, (1857).
During the 1970s the library grew rapidly and operated out of San Francisco as an international resource for psychoactive drug research, and for the study of psychoactive drug use in contemporary and historical societies. The Ludlow Library flourished during a period of perhaps the most intense media interest ever focused on the personal, social, scientific and political aspects of drug experience.
The library was curated by Michael Aldrich, holder of the first Ph.D. ever granted from an American University in the history of cannabis, and included on its board of advisors a number of eminent researches and writers, including Chauncey Leake, Richard Evans Schultes, Albert Hofmann, Alexander Shulgin, Andrew Weil, Oscar Janiger, Ralph Metzner, Laura Huxley, Allen Ginsberg and Lawrence Ferlinghetti.