Ixodid ticks were collected from medium-sized to large mammals in Ehime Prefecture, Shikoku, Japan. Ten species of ticks (Amblyomma testudinarium, Dermacentor taiwanensis, Haemaphysalis flava, H. formosensis, H. hystricis, H. longicornis, H. megaspinosa, Ixodes nipponensis, I. ovatus, and I. tanuki) were collected from a total of 29 mammals comprising 11 species. Haemaphysalis hystricis, a possible vector of Japanese spotted fever in Ehime prefecture, was collected from Canis lupus familiaris (domestic dog), Martes melampus melampus, and Sus scrofa leucomystax. This is a first report of H. hystricis from the domesticated dog in the endemic area of Japanese spotted fever. This suggests that it is necessary to pay attention to dogs as a host of the vector ticks for Japanese spotted fever control. Nyctereutes procyonoides and Ma. melampus are new hosts for A. testudinarium. Nyctereutes procyonoides, Mustela itatsi, and Lepus brachyurus are new hosts for H. formosensis. Martes melampus is a new host for H. hystricis.