Spilosoma pteridis, the brown tiger moth, is a moth in the family Erebidae. It was described by H. Edwards in 1875. It is found in western Oregon and Washington, British Columbia and northern Idaho. The habitat consists of wet forests west of the Cascades, including coastal rainforests, low elevation mixed hardwood-conifer forests, as well as higher elevation conifer forests in the Cascades. The larvae probably feed on various herbaceous plants.