Weasels Mustela spp. are specialized, small predators which demonstrate pronounced differences in size and social status according to sex and age, and these differences may manifest in spatial patterns including home range size and habitat selection. In forested North America, favored prey (voles; Microtus spp. and Myodes spp.) of short-tailed weasels Mustela erminea often reach high abundances in early stage forest, but availability of that cover type is limited where intensive plantation forestry occurs. We estimated home range size, including home range core area and arrangement, habitat selection, wet season rest site reuse and movements for 25 (18 M: 7 F) short-tailed weasels Mustela erminea that we radio-collared in managed plantation forests in western Oregon, USA in 2012–2013. Average fixed kernel 90% home range size was 51.3 hectares for males (95% confidence interval = 30.8–71.7 ha) and 8.6 hectares for females (95% confidence interval = 6.41–10.79 ha). Juvenile males had larger core areas than adult males, and all females had similar core areas. Core areas for all individuals were negatively correlated with % early stage forest cover. Females strongly selected early stage forest cover at both study area and home range scales, and males were less selective of particular cover types. Home ranges of observed males did not overlap, but partly overlapped the home ranges of females. Short-tailed weasels reused the same rest site in 43% ± 4 (mean ± SE) of cases observed during the wet season (n = 10 individuals, 292 rest sites). We conclude that space use by short-tailed weasels in western Oregon is influenced by sex, age, and cover type, especially availability of early stage forest, in managed conifer forests.