Sister Olive (1918âÂÂ1945) was an Australian racehorse that won the 1921 Melbourne Cup.
After finishing 4th in the 1921 Caulfield Cup, Sister Olive won the Melbourne Cup as a three-year-old in the same year, with a three length margin. Her win was only the third and, as of August 2021, the most recent by a three-year-old filly. Starting at odds of 16/1 and carrying 6 st. 9 lbs. (42.18 kg) she beat a field of 25, including Eurythmic, the favourite that finished last. Before the race, jockey Ted O'Sullivan considered her a "a good thing". It was his first and only Melbourne Cup win.
She came second in the 1922 VRC Australian Cup.
Sister Olive was the dam of Manolive, winner of the C F Orr Stakes and the Perth Cup and Mount of Olives, that won the South Australian Derby.