Cell-based seafood is produced by taking cells from live aquatic animals and cultivating them in appropriate growth media within bioreactors. Resultant products have identical DNA and tissue and appear safe for human consumption. They might present a viable alternative to wild-caught and farm-raised seafood in the future. This could take pressure off aquatic ecosystems and mitigate severe animal welfare concerns within the seafood industry. Numerous aquatic species are recognized to be sentient and capable of suffering, and many common rearing, catching, transporting, and slaughtering practices raise substantial animal welfare concerns. Because of compromised animal welfare, conventional seafood production in Japan has repeatedly attracted adverse international media attention. This study provides a first examination of Japanese consumer attitudes when presented with the opportunity to consume cell-based seafood instead of, or in addition to, conventional seafood. Attitudes and behavioral intentions were found to be positive overall, but extensive information campaigns appear to be necessary for the success of these products in the Japanese market. Numerous consumers expressed the desire for more information about cell-based seafood production and about how product safety can be guaranteed.