Green innovations represent an important factor in the sustainable development and competitiveness of gastronomic tourism destinations. This study aims to examine the relationship between green innovations and the perceived sustainable competitiveness of gastronomic tourism destinations, while analyzing the mediating role of perceived gastronomic authenticity. The research was conducted on a sample of 245 stakeholders involved in the organization and implementation of five major gastronomic festivals in Serbia. Data were collected using a structured questionnaire, and the proposed conceptual model was tested using the PLS-SEM method. The results indicate that green innovations are positively associated with perceived gastronomic authenticity and the perceived sustainable competitiveness of destinations. Furthermore, perceived gastronomic authenticity is positively associated with perceived sustainable competitiveness and mediates the relationship between green innovations and the perceived sustainable competitiveness of destinations. The findings suggest that the implementation of sustainable practices and the preservation of gastronomic authenticity are associated with stronger long-term sustainability and competitiveness of gastronomic tourism destinations, providing useful guidance for event organizers and tourism policymakers.