Calothamnus sanguineus, commonly known as silky-leaved blood flower, is a plant in the myrtle family, Myrtaceae and is endemic to the south-west of Western Australia.

[3][4] The flowers are bright red, sometimes white, and have 4 sepals, 4 petals and 4 claw-like bundles of stamens.

(Calothamnus torulosus has similar flowers but the upper stamen bundles are not fused in that species.)

[7] Calothamnus sanguineus is found from Cape Naturaliste to Kalbarri in the Avon Wheatbelt, Esperance Plains, Geraldton Sandplains, Jarrah Forest, Mallee, Swan Coastal Plain and Warren biogeographic regions.

[4] Calothamnus lateralis is classified as "not threatened" by the Western Australian government department of parks and wildlife.