This chapter reviews the current landscape of tourism seasonality within academic and institutional literature. It begins by analyzing 26 definitions published between 1975 and 2023, noting a lack of homogeneity that reflects the complex, multidimensional nature of the phenomenon. A systematic review of 151 studies identifies key research objectives, including the impacts of climate change, economic consequences, and strategies for mitigation. Thematic clustering reveals that research is dominated by demand-side dynamics and visitor behavior, while institutional factors and labor market variables remain comparatively underexplored. Analysis of research timelines indicates a peak in activity between 1993 and 2004, followed by a gradual decline in the most recent decade. Methodologically, the literature shows a heavy reliance on monthly data and quantitative techniques, particularly time series analysis, which can overlook the lived realities and adaptive strategies of local stakeholders. Furthermore, a significant geographical bias exists toward Europe and the Global North, leaving climate-vulnerable regions in the Global South underrepresented in empirical research. The chapter concludes by calling for more integrative, inclusive, and theoretically grounded research on the topic. By identifying these gaps and concentrations, the chapter serves as a diagnostic tool for the current state of knowledge and a roadmap for future academic inquiry.