Paeromopus angusticeps is a species of millipede found in the U.S. state of California. It occupies the largest geographic range of all four species of Paeromopus, occupying much of Northern California in a large arc extending from Monterey County on the central coast, north along the Coast Ranges to Humboldt County, and descending along the Cascades and Sierra Nevada range of eastern California. P. angusticeps is largely absent from California's Central Valley.
Adult P. angusticeps individuals possess up to 80 body segments and range from 100 to 150 mm long, and 5 to 7 mm wide. The color pattern consists of alternating bands of brown on a black or blue-black base color, although in some individuals the banding is largely indistinct from the base color. Like other members of the family Paeromopodidae, the exoskeleton is marked with small parallel grooves or striations. Each eye is composed of up to 30 ocelli arranged in a patch on each side of the head.