Ronald William "Josh" Kirby (November 27, 1928 - October 23, 2001) was an English commercial artist born in Waterloo, Merseyside County, on the outskirts of Liverpool, England. He was well known as the cover artist for many of Terry Pratchett's Discworld novels and has contributed to various role-playing game supplements.
Kirby studied at the Liverpool City School of Art, where he acquired the nickname Josh, which comes from being compared to 18th century English painter Sir Joshua Reynolds. He has also created poster art for the movies Monty Python's Life of Brian and The Return of the Jedi.
He died unexpectedly of natural causes in Norfolk County, England, at the age of 72.