Hypocalymma phillipsii is a species of flowering plant in the myrtle family Myrtaceae, and is endemic to a restricted part of Western Australia.

It is an erect, spreading shrub with elliptic to very broadly egg-shaped leaves, and white flowers arranged singly or in pairs in leaf axils, with 30 to 50 stamens in several rows.

[2][3][4][5] Hypocalymma phillipsii was first formally described in 1858 by William Henry Harvey in the Natural History Review from specimens raised in the Botanic Gardens of Dublin in 1856–58, from seeds received from the "neighbourhood of King George's Sound", collected by William Phillips.

[2] This species of Hypocalymma is restricted to the Stirling Range, where it grows in sandy soil amongst rocks in dense scrub on hillslopes at altitudes between 400 and 800 m (1,300 and 2,600 ft).

[2][4][5] Hypocalymma phillipsii is listed as "Priority Four" by the Government of Western Australia Department of Biodiversity, Conservation and Attractions,[5] meaning that is rare or near threatened.