Walt Willis (Walter Alexander Willis) (1919-1999) was a science fiction fanzine editor from Belfast, Ireland.
Willis was awarded a 1958 Hugo Award as "Outstanding Actifan" (active fan), which replaced the Best Fanzine category that year. He was nominated for a best fan writer Hugo in 1969 and two retro-Hugos in the same category (in 2001, 2004 for work in 1951, 1954). In 1959 and 1957 he was nominated in the fanzine category for Hyphen, and he received fanzine retro-Hugo nominations in 2004 for Slant and Hyphen. He shared a retro-Hugo for Slant with that fanzine's art editor James White.
His best known single work is The Enchanted Duplicator (1954), co-written with Bob Shaw, an allegory of a fan's quest to produce the perfect fanzine.
Willis was known for his writing for other zines, especially for the column "The Harp That Once or Twice" that began in the US fanzine Quandry, edited by Lee Hoffman, in 1951. This led to Willis's fame in US science fiction fandom and to his attending the 1952 Worldcon in Chicago as a special guest, recipient of travel funds raised by fans, under the leadership of fan Shelby Vick, who called the fund-raising 'the Willis Campaign', with the slogan, "WAW with the crew in '52!' which led to the establishment of the annual TransAtlantic Fan Fund.
He published one book professionally, under the pseudonym Walter Bryan: The Improbable Irish (1969), a linked sequence of mostly humorous essays about Ireland's history and its people.
In 1980, Richard Bergeron, also a former publisher of Willis's fan writing, produced a 600-page hardcover mimeographed fanzine, issue 28 of his fanzine Warhoon, devoted to collecting most of Willis's writings.