Calytrix sagei is a species of flowering plant in the myrtle family Myrtaceae and is endemic to a restricted area in the south-west of Western Australia.

It is a shrub with narrowly oblong to egg-shaped leaves with the narrower end towards the base, and yellow or cream-coloured flowers with about 15 to 25 stamens in several rows.

[2][4] The specific epithet (sagei) honours Leigh Sage, who was a joint collector of the type specimens, and who worked extensively on the taxonomy of the Goodeniaceae.

[2] This species of Calytrix grows in a range of habitats, including on the edges of salt lake and in sandy clay between Beverley and near Narembeen in the Avon Wheatbelt bioregion of south-western Western Australia.

[2][5] Calytrix sagei is listed as "Priority Two" by the Government of Western Australia Department of Biodiversity, Conservation and Attractions,[5] meaning that it is poorly known and from one or a few locations.