Environmental hazards—whether stemming from natural or human-induced disasters—pose a significant and escalating threat to communities worldwide. The growing frequency and unpredictability of such occurrences amplify the urgency for innovative solutions in monitoring, risk evaluation, and disaster response. This chapter delves into the transformative role of remote sensing (RS) and geographic information systems (GIS) in enhancing environmental hazard management, highlighting their capabilities in real-time data acquisition, spatial analysis, and informed decision-making support. This present chapter explores the synergistic advantages of RS and GIS in identifying vulnerable zones, simulating hazard impacts, and supporting emergency response planning. It examines the integration of high-resolution satellite imagery, LiDAR, drone-generated data, and geospatial datasets across diverse applications such as flood modeling, urban heat island mitigation, coastal erosion monitoring, and postdisaster evaluations. A collection of case studies from varied geographical contexts—including the UK, USA, India, and Nigeria—demonstrates the practical deployment of these technologies in real-world hazard scenarios. The chapter further highlights emerging technological advancements—such as 3D terrain mapping, real-time data analytics, AI-driven geospatial interpretation, and crowd-sourced GIS—which significantly expand the capabilities and effectiveness of hazard mitigation efforts. Despite notable progress, critical challenges persist, including limited data accessibility, high implementation costs, and shortages of skilled professionals, particularly in resource-constrained regions. Interdisciplinary collaboration, continuous innovation, and targeted capacity building are essential to positioning RS and GIS at the core of disaster risk reduction frameworks, reinforcing global efforts in resilience-building, sustainable development, and climate adaptationClimate adaptation.