Allocasuarina muelleriana, commonly known as slaty sheoak,[2] is a species of flowering plant in the family Casuarinaceae and is endemic to southern continental Australia.

[2][3][4] Slaty sheoak was first formally described in 1856 by Friedrich Anton Wilhelm Miquel who gave it the name Casuarina muelleriana in the journal, Nederlandsch Kruidkundig Archief from specimens collected in the Mount Lofty Ranges by Ferdinand von Mueller.

[7][8] Johnson described three subspecies of A. muelleriana in the Flora of Australia and the names are accepted by the Australian Plant Census: Allocasuarina monilifera grows in heath and scrub.

Subspecies muelleriana occurs from Ceduna and the Flinders Ranges, including Kangaroo Island in South Australia to Bendigo in Victoria.

Subspecies alticola is found in the north-eastern part of the species' range from the Freeling Heights to Wilpena Pound and subsp.