The Mediterranean Diet (MD), recognized for its significant health benefits and cultural value, has been inscribed by UNESCO as an Intangible Cultural Heritage of Humanity. This study explores the knowledge and adherence to the MD among undergraduate tourism students in the Mediterranean region of the Balkans, specifically in Slovenia, Croatia, and Montenegro. A total of 581 students completed a self-administered questionnaire assessing MD knowledge, and the KIDMED scale was used to evaluate adherence. The results revealed an average level of MD knowledge overall, with Slovenian students achieving the highest scores. By contrast, adherence was highest among Montenegrin students, who nevertheless scored the lowest in knowledge. No significant correlation was found between MD knowledge and adherence, suggesting that factors beyond formal education contribute to dietary behavior. Further analysis showed that academic performance and tourism-related work experience were associated with higher knowledge but not with adherence. Conversely, reliance on informal sources—such as family, friends, and cookbooks—was positively associated with adherence levels. These findings highlight the important role of informal learning in shaping students’ dietary practices. Given the potential influence of tourism students on the promotion of sustainable food practices, it is essential to integrate diverse educational approaches that bridge the gap between knowledge and actual adherence to the principles of the MD.