The core objective of this chapter is to explore the symbiotic relationship between the marine tourism and the sustainability of the blue economy. This chapter delves the contributions marine tourism has made to the sustainable development of the blue economy showing the importance of marine tourism for fostering economic development, enhancing social well-being, and safeguarding the ecosystem within the blue economic context. The study found marine tourism boosts blue economy by creating jobs in coastal communities, stimulating infrastructure development, and generating revenue. As it promotes cross-cultural interaction, local empowerment, and the preservation of heritage, marine tourism is beneficial to the society also. Furthermore, marine tourism acts as catalyst for environmental sustainability through environment-friendly tourism, conservation efforts, and the preservation of the ocean resources. Along with highlighting the positive impact of marine tourism on the blue economy, the chapter also tries to show the numerous challenges marine tourism poses on the sustainability of blue economy. Finally, by demonstrating some successful marine tourism initiatives worldwide as well as by providing a few recommendations, the study emphasizes the importance of collaboration among the government, industry participants, policymakers, and stakeholders to support a blue economy—compliant with sustainable marine tourism practices.