Coastal regions represent some of the world's most popular tourism destinations, attracting millions of visitors annually while simultaneously facing unprecedented environmental pressures and climate change challenges. This paper examines sustainable tourism development practices in coastal areas through a comprehensive case study approach, analyzing successful implementation strategies, challenges, and outcomes across diverse geographical contexts. The research evaluates three distinct coastal destinations: the Great Barrier Reef Marine Park in Australia, the Riviera Maya in Mexico, and the Algarve region in Portugal. Through comparative analysis of policy frameworks, community engagement initiatives, environmental management practices, and economic outcomes, this study identifies key success factors and best practices for sustainable coastal tourism development. The findings reveal that integrated management approaches combining environmental protection, community participation, and economic viability are essential for long-term sustainability in coastal tourism destinations.