Eleven nominal species (Acanthochondria uranoscopi in the Chondracanthidae; Conchyliurus quintus in the Clausidiidae; Pseudomacrochiron aureliae in the Macrochironidae; Ostrincola japonica and Ostrincola koe in the Myicolidae; Colobomatus mylionus in the Philichthyidae; Ceratosimicola japanica and Splanchnotrophus helianthus in the Splanchnotrophidae; Enterognathus inabai in the Enterognathidae; Neomysidion rahotsu in the Nicothoidae; Creopelates nohmijimensis in the Pennellidae) and six families (Clausidiidae, Macrochironidae, Philichthyidae, Splanchnotrophidae, Enterognathidae, Nicothoidae) are newly added to the checklist of the parasitic copepods of fishes and invertebrates of the Seto Inland Sea, Japan, published in 2011. Now, 99 nominal species (81 species from fishes and 18 species from invertebrates) in the following 25 families of the parasitic copepods are known to occur in the Seto Inland Sea: Anthessiidae (2 spp.), Bomolochidae (7 spp.), Caligidae (15 spp.), Chondracanthidae (8 spp.), Clausidiidae (1 sp.), Enterognathidae (1 sp.), Ergasilidae (3 spp.), Hatschekiidae (9 spp.), Kroyeriidae (1 sp.), Lernaeopodidae (9 spp.), Lernanthropidae (7 spp.), Lichomolgidae (2 spp.), Macrochironidae (1 sp.), Mantridae (1 sp.), Myicolidae (3 spp.), Mytilicolidae (2 spp.), Nicothoidae (1 sp.), Notodelphyidae (2 spp.), Pandaridae (1 sp.), Pennellidae (3 spp.), Philichthyidae (1 sp.), Pseudocycnidae (1 sp.), Pseudohatschekiidae (1 sp.), Splanchnotrophidae (2 spp.), and Taeniacanthidae (15 spp.). Corrections are made for the information on the anthessiid Panaietis yamagutii erroneously reported in the 2011 version of the checklist.