Sir William Dunn, 1st Baronet, of Lakenheath, MP, JP, FRGS (22 September 1833 – 31 March 1912), was a London banker, merchant and philanthropist, Liberal Member of Parliament for Paisley (1891–1906), and from before 1896 until the outbreak of the Second Boer War in 1899 consul general for the Orange Free State in the United Kingdom.