Craspedocarpus has seven currently described species from the western Atlantic and South Pacific Oceans. The genus is characterized by well-developed rosettes of small outer cortical cells, marginal proliferations, discoid holdfasts, carposporophytes with several large central cells and zonate tetrasporangia. Craspedocarpus jindoensis sp. nov. collected from Jindo, Korea, is here described as a new species on the basis of morphological and molecular data. The new species is characterized by having fan-shaped thalli, smooth margins, subdichotomous branching pattern, incomplete pseudoparenchymatous medulla with filaments, and tetrasporangial sori and cystocarps both in fronds and proliferations. Phylogenetic analysis of rbcL also placed C. jindoensis sp. nov. in Craspedocarpus and distinguished it from congeners. The sequence divergences between C. jindoensis sp. nov. and the other species of Craspedocarpus, C. erosus, C. tenuifolius and C. venosus are 2.9%–3.2%, respectively.