Sumac sour, a local product unique to the Kahramanmaraş region of Turkey, holds a significant place in the local cuisine with its distinctive tart flavor and cultural heritage. This chapter presents a theoretical study on how the sumac sour product can be associated with gastronomic tourism through fusion cuisine applications. Based on an extensive review of current literature, the concepts of gastronomy tourism, fusion cuisine approaches, and the roles of local products in authenticity and sustainability are examined. The gastronomic and cultural value of sumac sour is detailed; its traditional uses in Kahramanmaraş cuisine and potential for fusion with other culinary traditions are discussed. A literature-based SWOT analysis evaluates the strengths and weaknesses, as well as opportunities and threats, of utilizing sumac sour in gastronomic tourism. In conclusion, the study demonstrates that creative uses of sumac sour in fusion cuisine can contribute to the sustainability of local food culture while offering gastronomic tourists unique and authentic experiences. The chapter is prepared in line with international academic standards and concludes with recommendations for future research and practice.