Abstarct This study focuses on quantifying the impacts of climate change on international tourism in Turkey through the estimation of the future number of international tourists for different tourism destinations. For this purpose, 30 tourism destinations were selected from different regions in Turkey offering different kinds of tourism attributes and climatic conditions. Future tourism demand was estimated based on comfort level change, a major determinant of tourist preference, and evaluated through the Tourism Climate Index. Changes in climate comfort levels between a base period (1963-2017), a projected medium term period representing the 2050s (2040-2069), and a projected long term period representing the 2080s (2070-2099) were correlated with the number of international tourists using a regression model developed by Hein et al. (Current Opinion in Environmental Sustainability,1:170-178, 2009). The results of this study project extreme drops in demand, seasonal shifts, and the emergence of new alternative destinations. The study is significant as the first quantitative evaluation of climate change impacts on tourism demand in Turkey through a comparison of the spatial exposures of destinations. The results will help lead the way to a national tourism development roadmap in Turkey through the revelation of regional risks and opportunities and will serve as a benchmarking study for tourism destinations that have similar climate conditions and tourism patterns.