Prostanthera grylloana is a species of flowering plant in the family Lamiaceae and is endemic to Western Australia.

[2][3] Prostanthera grylloana was first formally described in 1876 by Ferdinand von Mueller in his book Fragmenta phytographiae Australiae from specimens collected "in the desert around Ularing" by Jess Young.

[4][5] The specific epithet (grylloana) honours the actress Adelaide Ristori, the wife of the marchese Giuliano Capranica del Grillo.

[5][6] This mintbush grows on granite outcrops and ridges and on stony hills and undulating plains in the Avon Wheatbelt, Coolgardie, Mallee and Murchison biographic regions of Western Australia.

[2][3] Prostanthera grylloana is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife.