Edward Gordon Duff (16 February 1863 – 28 September 1924), known as Gordon Duff, was a British bibliographer and librarian known for his works on early English printing.

Duff was born in Liverpool on 16 February 1863. He was educated at Cheltenham College and Wadham College, Oxford, where he took a degree in classics in 1887.

Duff began work on a catalogue of incunabula in the Bodleian Library but did not finish the project. In 1893 Enriqueta Augustina Rylands appointed Duff her librarian. From 1893 to 1899, he compiled the first catalogue of the John Rylands Library, Catalogue of the Printed Books and Manuscripts in the John Rylands Library, Manchester (Manchester: J. E. Cornish, 1899). Henry Guppy was appointed joint librarian in 1899. Duff resigned from his position at the John Rylands Library in October 1900 and, for the rest of his life, he supported himself by doing freelance work and by taking academic appointments.

He was Sandars Reader in Bibliography at the University of Cambridge in 1903 and spoke on "The printers, stationers and book-binders of London, 1500–1535." and again in 1911 speaking on "English provincial printers, stationers and book-binders to 1557."

Duff died at his home in Oxford on 28 September 1924.