A new skipper butterfly Chaetocneme richardsi n. sp., from the Upper Sepik, West Sepik Province, Papua New Guinea, is described and figured. The new species lacks a forewing costal fold and is compared with putative related species in the helirius and tenuis species groups of Chaetocneme Felder, 1860, particularly the Bismarckian endemic C. sombra Evans, 1934.