Sarah (Sally) Hynes MBE (30 September 1859 – 27 May 1938) was a Polish-born, Australian botanist and teacher. Sarah (Sally) Hynes was born on 30 September 1859 in Danzig, Prussia (now Gdansk, Poland) to William John Hynes (1831–1909), a master mariner and his wife Eliza Bell. Sarah was educated at Edinburgh Ladies' College, Upton House in St John's Wood, London, and at Chichester College in Sussex. She earned a botanical certificate from South Kensington Museum, Science and Art Department.