Three Chordaria species were reported from the Russian Far East, viz. C. chordaeformis, C. flagelliformis, and C. gracilis. Chordaria flagelliformis and C. gracilis are common and widely distributed in the Bering Sea and Kamchatka, Kuril Islands, and the Sea of Okhotsk, while C. chordaeformis was only reported from the Avacha Bay (southeast Kamchatka). We describe a new species, Chordaria okhotskensis, from the Taujskaya Bay (northern Sea of Okhotsk, Russia). The external morphology of C. okhotskensis is similar to C. chordaeformis in having unbranched or sparsely branched thalli with branches borne at acute angles. The new species differs from C. chordaeformis in having large elongate medullary cells and thalli that are entirely flattened. Phylogenetic analysis based on rbcL gene data showed that this new species from the Sea of Okhotsk is distinct from the Atlantic and Pacific types of C. chordaeformis. Based on the phylogenetic results, the Kamchatka specimens of C. chordaeformis were also attributed to a new taxon, C. okhotskensis.