Monoon michaelii is a plant in the custard apple family Annonaceae found only in a very small part of the Wet Tropics bioregion of Queensland, Australia.

Monoon michaelii is a tree to 30 m (98 ft) tall, the shoots and young branches are covered in soft fine hairs.

[4][5][6] The inflorescences take the form of a fascicle or raceme, are produced in the leaf axils or directly from the branches (a process known as ramiflory).

Saunders, et al. reviewed the genus Polyalthia, and in the process they gave this species the new combination Monoon michaelii.

[7][2][4] The species epithet michaelii is in honour of Norman Michael, an Anglican minister and active plant collector in Queensland.