Milnepanopeus n. gen. is proposed to accommodate the western Atlantic brachyuran crab, Hexapanopeus lobipes. Characters of the carapace, sternal groove, carpus of the ambulatory pereiopods, and male first gonopod define this presently monospecific genus. Recent molecular analyses support removal of H. lobipes from Hexapanopeus, and segregate this genus as a distinct lineage of Panopeidae Ortmann, 1893. The species is redescribed as Milnepanopeus lobipes, n. comb., on the basis of the holotype and supplementary material from deep banks in the Gulf of Mexico. Variations in morphology are addressed along with morphological comparisons to related genera of the family.