Lethe was a science fiction fanzine by Jack Riggs.
Lethe was published in Berkeley California, U.S.A. in the 1940s.
Issue #8 appeared in February 1948. Nine issues were published.
Jack Riggs attended the February 1945 Boskone Convention in Boston, sponsored by The Stranger Club, and held in the home of R.D. Swisher.
Withe fellow fan Louis C. Smith, he released the fanzine Unknown Index in 1946, which was a bibliography and index to Unknown Magazine, a magazine of science fiction, fantasy, and weird fiction.