Mammalian species in northern Australia are declining. The resources that many species from this region require to persist in the landscape remain poorly understood. We examined habitat selection and diet of the scaly-tailed possum (Wyulda squamicaudata, hereafter called Wyulda) in the north-west Kimberley, Western Australia, in relation to variation in complexity of rocky habitat, habitat heterogeneity, and recent fire history. We fitted GPS tags to 23 Wyulda between January 2013 and February 2014 and analysed step selection between GPS fixes to describe habitat choice. We assessed diet by microscopic analysis of plant fragments from 47 faecal samples. Individual Wyulda preferentially foraged in locations with high rock complexity and high habitat heterogeneity in a wide variety of habitats, but denned exclusively in complex rock piles. They used savannas of a range of post-fire ages, including recently burnt (1–2 months after fire) and long unburnt (>24 months after fire). They were highly frugivorous with, on average, 77% of plant fragments per scat sample identified as fruit epidermal layers. Overall, rock complexity appears to be an important landscape attribute for Wyulda, as it may provide den sites and protect fire-sensitive landscape features such as fruiting trees and habitat heterogeneity.