Information on the monogeneans parasitic on fishes and invertebrates of the Seto Inland Sea published between the years 1894 and 2015 with two new records is assembled as Parasite-Host and Host-Parasite lists. A total of 54 species (52 species from fishes and 2 species from invertebrates) of the following families have been reported: Monocotylidae (3 species), Capsalidae (6), Anoplodiscidae (1), Udonellidae (1), Dactylogyridae (2), Ancylocephalidae (6), Diplectanidae (11), Hexabothriidae (1), Mazocraeidae (1), Diclidophoridae (7), Plectanocotylidae (1), Bychowskicotylidae (1), Gastrocotylidae (1), Axinidae (3), Heteraxinidae (2), and Microcotylidae (7). Anoplodiscus spari and Dactylogyryus gotoi are herein reported for the first time from the Seto Inland Sea off Hiroshima Prefecture.