Olive Blanche Davies MSc (27 October 1884 – 1976/7) was an Australian botanist and botanical artist, noted for being co-author with Alfred Ewart of their 1917 book The Flora of the Northern Territory, and for producing many of the illustrations. Olive was born Toorak, Victoria, the youngest of six children of Elizabeth Locke Mercer (*c1850) from Kirkcudbright and Sir Matthew Henry Davies (1850-1912) of Geelong. The standard author abbreviation O.B.Davies is used to indicate this person as the author when citing a botanical name.