As climate change intensifies, coastal cities are increasingly vulnerable to ecological degradation, extreme weather events, and socio-economic disruption. This chapter explores how nature-based solutions (NBS), particularly those centred on blue carbon ecosystems such as mangroves, seagrasses, and macroalgae, can support multidimensional urban resilience in coastal tourism cities. Using Cancún, Mexico, as a representative case, the chapter identifies three interrelated challenges—ecological vulnerability, economic dependence, and fragmented governance—and proposes a strategic framework that integrates ecological restoration, economic transition, and community participation. To structure this framework, the chapter introduces three innovative blue carbon zones: dynamic coastal buffers, stable ecological anchors, and urban micro-wetlands, each targeting different resilience functions. Three international case studies (Tokyo Bay, Pulicat Lake, and Arcata Wetlands) illustrate diverse NBS implementation models, from top-down engineered approaches to grassroots, community-led initiatives. These cases inform a hybrid strategy tailored to Cancún: dynamic carbon sinks such as Sargassum buffers for coastal protection, stable carbon sinks like mangrove reforestation for water quality and long-term sequestration, and urban-scale micro-wetlands for public engagement. The chapter argues that blue carbon-based NBS can act not only as a climate mitigation tool but as an integrated green solution that links environmental recovery with inclusive urban development and climate justice.