This article explores attitudes of hospitality stakeholders (HSs) and consumers towards fish gastronomy in the Czech Republic with an emphasis on traditional recipes and the impact of globalization. For the exploration of HSs’ attitudes, qualitative investigation via in-depth semi-standardized interviews was employed with 19 fish restaurant HSs. The abstraction, appearance of ideal types of HSs, and integration with four aspects of Ritzer’s McDonaldization theory were done. For the exploration of consumers’ attitudes, sensory evaluation of seven fish dishes with 1698 participants was used. Lastly, a focus group was conducted with regular fish food consumers. Three ideal types of HS named progressive innovators, taste defenders, and occasional traditionalists appeared. For all of them, aspects of McDonaldization were obvious, meaning shift towards rationalization in Czech fish culinary culture and possible dilution of the original identity. As the main reasons for deauthentication of Czech fish gastronomy, a high laboriousness of traditional fish dishes causing high time consumption for restaurant staff, and the inclusion of bones in most of the traditional Czech fish dishes as the main barrier for consumers were identified. Paradoxically, consumers preferred traditional dishes more, showing a discrepancy between the attitudes of consumers and HSs. This result drew attention to the need for marketing research on the part of HSs. When already prepared dishes were presented, consumers preferred to choose more time-consuming fish dishes with more input ingredients. In the restaurant, consumers more often choose bone-free dishes. On the other hand, in households, consumers prefer the cheaper purchase of whole fish with bones. Ways of defense against food globalization were outlined: promotion of traditional fish dishes not contradicting the McDonaldization aspects, supporting food with strong national traditions, and the usage of glocalization when the skills, specificity, or original ingredients are sustained despite globalization.