Water resources management in the coastal and island tourism destinations faces many challenges and threats driven by climate change and socio-economic stressors, especially in developing countries. Understanding the perceptions of a range of stakeholders, including tourism providers, on the perceived importance of water resources management subject to climate change and tourism development in these destinations is, therefore, needed for a long-term strategy satisfying a growing water demand from socio-economic development. This study applies both logistic regression models and Bayesian networks to explore the determinants affecting the respondents’ perceptions and willingness to pay (WTP) for building reservoirs and increasing water price on Cat Ba Island, Vietnam subject to climate change and tourism development. Our findings show that about 83.5% of respondents are willing to contribute to the construction of reservoirs, while only 26.2% of respondents are supporting higher water prices in the island. Climate change and tourism development were found to be the strongest factors causing water shortage and in turn affecting the respondents’ WTP for building reservoirs and increasing water price, followed by occupation and monthly income. Such perceptions and experiences of a variety of stakeholders on the nexus of tourism development, water resources management and climate change can contribute to formulating policies and decision-making support, thereby potentially strengthening the tourism industry, and protecting the water resources under climate change on Cat Ba Island.