A new marine interstitial nematode species belonging to the subgenus Quadricoma of order Desmoscolecida is described from Jindo Island, South Korea. The new species, Tricoma (Quadricoma) jindoensis sp. nov., is most allied with T. (Q.) crassicomoides Timm, 1970 in sharing the similar cephalic setae, broadly truncated border of head, lip region including 6 labial papillae, and slender and long spicule among the seven congeners with 44 quadricomoid rings. However, T. (Q.) jindoensis differs from it by the globular protuberance on the penultimate ring, 7 tail rings, and 9 pairs of subdorsal setae in male. This is the first record of Quadricoma nematodes from East Asia.