Algernon Bertram Freeman-Mitford, 1st Baron Redesdale (24 February 1837 – 17 August 1916), was a British diplomat, collector and writer, whose most notable work is Tales of Old Japan (1871).

After service in the Diplomatic Corps in Shanghai, he went to Japan in 1866 as second secretary to the British Legation at the time of the migration of the Japanese seat of power from Kyoto to Edo (modern-day Tokyo), known as the "Meiji Restoration".

[7][8] He later wrote Tales of Old Japan (1871), a book credited with making such Japanese Classics as "The Forty-seven Ronin" first known to a wide Western public.

[2] Following the 1902 Anglo-Japanese Alliance, in 1906 Mitford accompanied Prince Arthur on a visit to Japan to present the Emperor Meiji with the Order of the Garter.

[9] From 1874 to 1886, Mitford acted as secretary to HM Office of Works, involved in the lengthy restoration of the Tower of London and in landscaping parts of Hyde Park such as "The Dell".

He persuaded Edward VII to plant Japanese knotweed at Sandringham House and it later became difficult to eradicate, according to George VI.

[21] In his closing years, Lord Redesdale edited and wrote extensive and effusive introductions for two of Houston Stewart Chamberlain's books, The Foundations of the Nineteenth Century and Immanuel Kant: A Study and Comparison with Goethe, Leonardo da Vinci, Bruno, Plato, and Descartes, both two volumes each, translated into English by John Lees, M.A., D.Litt., and published by John Lane at the Bodley Head, London, in 1910 and 1914 respectively.

[25] Mitford died the following year, and the gravestone inscription for Clement was chosen by the family after the war: "AND SO HE PASSED OVER AND ALL THE TRUMPETS SOUNDED ON THE OTHER SIDE".