Calothamnus torulosus was first formally described by Johannes Schauer in 1843 in Dissertatio phytographica de Regelia, Beaufortia et Calothamno from a specimen collected at the top of the hill at the foot of the mountains of the Darling Range, not far from the town Maddington, now a suburb of Perth. The specific epithet is derived from the Latin word torosus, meaning bulging, muscular, fleshy or lusty.