The Brown Antechinus (Antechinus stuartii), also known as Stuart’s Antechinus and Macleay’s Marsupial Mouse, is a species of small carnivorous marsupial of the family Dasyuridae. The Brown Antechinus is found east of the Great Dividing Range in Australia, from southeastern Queensland to around Koloa, New South Wales. It is mostly found in forested habitats.
The Brown Antechinus is mostly nocturnal and is arboreal, and females build large communal nests shared by many individuals. Like all antechinuses, male Brown Antechinuses die after their first breeding season (which lasts two weeks) as a result of stress and exhaustion. Female Brown Antechinuses do not possess a pouch. The young must attach themselves to the teats (of which there are usually eight). Its diet includes beetles, spiders, amphipods and cockroaches, although it is an opportunistic feeder.
It was described in 1841 by the entomologist William Sharp Macleay.