India’s rivers are lifelines for agriculture, drinking water, industry, and cultural practices, yet they face mounting threats from both anthropogenic activities and climate change. This chapter provides a comprehensive review of river water contamination across India, focusing on the hydrogeochemical characteristics of pollutants—such as heavy metals, pesticides, and emerging contaminants like microplastics—and their impacts on human health and the environment. We discuss the major sources and pathways of river pollution, including industrial discharges, agricultural runoff, and urbanization, and highlight the bioaccumulation of toxic substances within aquatic food webs. The chapter also examines the socioeconomic consequences of waterborne diseases and ecosystem degradation. Persistent and future environmental crises are explored, emphasizing the role of increasing human modifications—such as damming, land-use change, and over-extraction—in exacerbating riverine stress. The review integrates recent advances in monitoring and remediation technologies, and underscores the importance of ecological restoration strategies. Finally, we analyze the implications of climate change for river system resilience and environmental sustainability, advocating for integrated management approaches to safeguard India’s riverine resources for future generations.