The conservation of threatened species often requires an examination of home range, foraging preferences, and diet. We used radio tracking, global positioning system data loggers, and fecal pellet analyses to study the nocturnal ecology of an endangered desert mammal, the sandhill dunnart, Sminthopsis psammophila. Twenty-four individuals were tracked between 2015 and 2018. The mean home range area of S. psammophila was 70 ha (100% minimum convex polygon). Reproductive males had a mean home range of 148 ha, whereas the ranges of all other groups were comparatively smaller. Sminthopsis psammophila preferred dense, long unburned foraging habitats. There was no effect of weather (excluding extreme cold/rain) on nocturnal ranging behavior. Ants comprised a significant proportion of the diet of S. psammophila and S. hirtipes, whereas S. dolichura consumed a broader range of prey. By integrating foraging and dietary analyses, we provide new insights to improve the conservation management of one of Australia's least studied but most threatened marsupials.