Olearia megalophylla, the large-leaf daisy bush, is a species of flowering plant in the family Asteraceae. It is a shrub up to 2 metres high with scattered leaves. These are dark green above and woolly underneath and are 20 to 120 mm long and 6 to 28 mm wide. The flowerheads have 5 to 9 white ray florets and 9 to 14 yellow disc florets. The species was first formally described by Ferdinand von Mueller in Papers and Proceedings of the Royal Society of Tasmania in 1859, and named Eurybia megalophylla. In 1865 he placed the species in the genus Aster and finally in Olearia in 1867. It occurs in moist sclerophyll forest in south-eastern New South Wales and Victoria.