Cyclocotyloides bergstadi n. sp. is described from the gills of grenadier, Coryphaenoides brevibarbis (Macrouridae), from the Mid-Atlantic Ridge, North Atlantic Ocean. The new species differs from Cyclocotyloides pinguis by being significantly smaller and by lacking a subterminal protuberance on the anteromedial sclerite of the clamp. The generic diagnosis of Cyclocotyloides is emended.