This research aims to explore the integration of land use, climate, and water resources for urban resilience in Bangkok, Thailand and Hanoi, Viet Nam, both of which are megacities of Southeast Asia. Climate projections using the WorldClim database for 2050 in Bangkok reveal an increase in temperature by 8.2 percent, while precipitation will tend to slightly decrease by 7.47 percent compared to 1960-1990. The model also forecasts warmer temperature by 10.97 percent and a slight decrease by 2.6 percent in precipitation in Hanoi by 2050. Scenario-based land use projection using the CLUMondo model reveals a higher urban expansion rate in Bangkok and Hanoi under “business as usual” (BAU) scenarios. Regarding the Green Growth (GG) scenario, forest cover in Hanoi is expected to increase at a higher rate than Bangkok by 2050. A projected increase in water demand by 2050 in both cities will come from agriculture and industrial expansion, an increase in the population, and higher living standards. Bangkok and Hanoi are particularly vulnerable to water shortage from less precipitation in 2050, which will cause water supply problems in the future. The combined impact of climate and land-use change by 2050 may lead to urban water supply problems. Urban planners and policymakers should consider the significant impacts of water security and prepare for city mitigation and adaptation to cope with these changes.