Tealliocaris sp. aff. T. loudonensis Peach (Peracarida, Crustacea) is reported for the first time from the Mississippian of North America. It is described from the Port au Port Peninsula of western Newfoundland where it occurs in a sequence of grey pelmicrites showing evaporitic solution features indicative of a hypersaline environment. The previously described peracarid Bellocaris newfoundlandensis Fong, which also occurs in the Port au Port area, has been found at several new localities in addition to the type locality. Bellocaris newfoundlandensis only occurs in buff-colored brachiopod–bryozoan packstones, occurring as karstic infill, where more normal marine water circulation probably was less inhibited.