The resurgence of populism and nationalism across diverse political contexts has profoundly altered the global tourism landscape. Tourism, once primarily framed through economic development, cultural exchange, and leisure mobility, has increasingly become entangled with ideological narratives emphasizing sovereignty, identity, security, and exclusion. This article offers a comprehensive theoretical and analytical exploration of how populist political movements and governments reshape tourism development, destination management, tourist behavior, and global travel patterns. Drawing strictly on established scholarly literature, the study synthesizes insights from political economy, cultural theory, sustainability studies, and tourism sociology to illuminate the multidimensional impacts of populism on tourism systems. The article adopts a qualitative, interpretive methodology grounded in critical literature analysis, enabling a deep engagement with conceptual debates rather than empirical generalization. Findings indicate that populist ideologies influence tourism through five interrelated mechanisms: the politicization of national branding, the securitization of mobility, the reconfiguration of sustainability discourses, the reshaping of overtourism narratives, and the transformation of the tourist gaze. Populist governance often promotes selective openness, privileging certain tourist flows while discouraging others, and reframes tourism as a tool of national affirmation rather than cosmopolitan exchange. At the same time, resistance to globalization embedded in populism generates paradoxical outcomes, as tourism remains economically indispensable even to nationalist regimes. The discussion critically examines these contradictions, addresses theoretical limitations, and identifies future research directions in a world marked by ideological polarization and mobility inequalities. The article concludes that understanding tourism in the age of populism requires moving beyond apolitical economic models toward a politically informed, ethically grounded, and socially reflexive framework.