Paracoccidiodomycosis ceti (PCM-C) is a zoonotic mycosis characterized by chronic granulomatous cutaneous lesions in cetaceans. It is distributed worldwide and is caused by an unculturable fungus; Paracoccidioides cetii. On the other hand, coccidioidomycosis (CCM), caused by Coccidioides spp., is also a zoonotic and highly pathogenic fungal infection endemic in both American continents. Even though the Far East is not an endemic area of CCM, an autochthonous case has been reported in China. Although the seroprevalence against P. cetii in captive dolphins was 61.0%, there is no information on wild dolphins living in cold waters. The present study aimed to investigate the seroprevalence against P. cetii and C. posadasii in 15 Dall's porpoises (Phocoenoides dalli) and 11 harbor porpoises (Phocoena phocoena) stranded in Hokkaido, Japan. The seroprevalence against P. cetii in the above dolphins was 26.9% (7/26), which was recorded only in Dall's porpoises (7/15), and that against C. posadasii was 15.4% (4/26), three in Dall's porpoises and one in harbor porpoise. The present study demonstrated positive seroprevalence against P. cetii and C. posadasii in wild cetaceans living in the subarctic areas of the Far East as the first records, and would issue the warning those who live in the area were exposed to the causative agent of CCM from seawater.