Fannie Eleanor Williams MBE, ARRC (4 July 1884 – 16 June 1963), known as Eleanor Williams, was an Australian scientist. She served as a bacteriologist during World War I, and was the third scientist and the first woman appointed to work at the Walter and Eliza Hall Institute of Medical Research after its establishment in 1915. She directed a laboratory studying infectious diseases, and had particular expertise in dysentery, hydatid disease and snake venom. She co-founded Australia's first blood bank.