The updated checklist of the marine crabs of Guinea-Bissau presented in this work is the result of consolidating decades of research, ongoing systematic revisions of the regional carcinofauna, and the inclusion of new records. DNA markers and morphological analyses for accurate identifications are integrated. Sixty-one species are mentioned in this list after reviewing specimens from scientific collections and literature. Of these 61 species listed, the presence of 51 species in Guinea-Bissau is confirmed, and 21 are reported for the first time in the area. A total of 98 sequences were obtained from 41 species (51 of 16S for 38 species and 47 of COI for 35 species), and 48 sequences (24 of 16S and 24 of COI) were the first ones obtained for 29 species. The maximum or minimum bathymetric range is expanded by 16 species, and for other six species, a color description is provided for the first time. Merocryptus obsoletus is synonymized as Merocryptus boletifer. The present study will be a useful baseline for gathering further ecological information about globally important marine taxa, not only in Guinea-Bissau but about African brachyurans in general.