Caleana terminalis, commonly known as smooth-billed duck orchid[3] is a species of orchid endemic to a small area near the Murchison River in the south-west of Western Australia.

[3][4] The smooth-billed duck orchid was first formally described in 2006 by Stephen Hopper and Andrew Brown who gave it the name Paracaleana terminalis.

The description was published in Australian Systematic Botany from a specimen collected from the Z Bend in the Murchison River Gorge near Kalbarri.

[5] In 2014, based on molecular studies, Joseph Miller and Mark Clements transferred all the species previously in Paracaleana to Caleana so that the present species became Caleana terminalis.

[1][6] The specific epithet (terminalis) is a Latin word meaning "of ends or boundaries",[7] referring to the callus being confined to the very tip of the labellum.