William Auld (6 November 1924 – 11 September 2006) was a British poet, author, translator and magazine editor who wrote chiefly in Esperanto.

Auld was born at Erith in Kent, and then moved to Glasgow with his parents, attending Allan Glen's School.

After wartime service as a spitfire pilot in the Royal Air Force, he studied English literature at Glasgow University, and then qualified as a teacher.

[1] In 1952 he married his childhood sweetheart Margaret (Meta) Barr Stewart, also an Esperantist, and had two children.

He donated his personal collection of nearly 5000 books in and about Esperanto to the National Library of Scotland, where it is now housed,[5] in 2001.