Western Australian peppermint, Swan River peppermint, peppermint and willow myrtle, is a species of tree that grows in the southern half of Western Australia. It has fibrous brown bark, and long, narrow, dull green leaves, with tightly clustered inflorescences of small white flowers in the axes. It grows in a weeping habit, and looks remarkably like the weeping willow from a distance. It is most readily identified by the powerful odour of peppermint that is emitted when the leaves are crushed or torn. Agonis flexuosa occurs in a sub-coastal strip from just north of Perth south and then east beyond Bremer Bay.

AUSTRALIAN PEPPERMINT is used as an inlay material on acoustic guitars, and as Stomp Box tonewood