Cyanothamnus ramosus is a species of plant in the citrus family Rutaceae and is endemic to the southwest of Western Australia.

It is an erect, mostly glabrous shrub with pinnate leaves with up to seven leaflets, and white, four-petalled flowers with blue or pale green backs.

The petals are white with blue or pale green backs, broadly elliptic, 3–5 mm (0.12–0.20 in) long and prominently glandular.

[2][3] This species was first formally described in 1839 by John Lindley who gave it the name Cyanothamnus ramosus and published the description in A Sketch of the Vegetation of the Swan River Colony.

[6] In a 2013 paper in the journal Taxon, Marco Duretto and others restored Lindley's name Cyanothamnus ramosus on the basis of cladistic analysis.