This study examines how tourism innovation contributes to sustainable destination development by integrating emerging theoretical perspectives across tourism research. An integrative literature review was conducted using Scopus records retrieved in 2026 and targeted verification of article metadata and full-text evidence where available. After deduplication, 34 unique records were screened and 32 were retained for thematic synthesis, comprising 11 core conceptual anchors and 21 supporting studies. The analysis identifies four overarching theoretical perspectives: innovation as transformation, sustainability transitions, innovation ecosystems and collective action, and sustainability-oriented innovation. Six recurrent mechanisms connect innovation with destination-level sustainability: knowledge and network integration, collaboration and co-creation, institutional governance and legitimacy, intermediation and ecosystem orchestration, digital and technological enablement, and place-based resource mobilization. The review proposes that tourism innovation generates economic, social, and environmental value through context-dependent mechanisms rather than through a linear innovation-to-sustainability pathway. The study contributes a mechanism-oriented synthesis for tourism destination research and clarifies implications for destination managers seeking to align innovation with long-term sustainability.