This chapter focuses on urban water demand management, a critical strategy for enhancing water security in growing cities. Traditional water management has relied on supply-side solutions, such as large-scale infrastructure projects like dams and reservoirs. However, these solutions are often costly, environmentally damaging, and politically contentious. In contrast, demand-side management seeks to reduce water consumption and optimise existing water resources, making it a more sustainable and cost-effective approach. Urban water demand management aims to change societal behaviours, attitudes, and practices towards water use. By implementing water conservation strategies, urban managers can decouple water demand from economic and population growth, reducing pressure on municipal water supplies. The chapter explores various demand management tools, including pricing mechanisms, water trading, metering, active leak detection, and alternative water supplies like rainwater harvesting and greywater systems. Additionally, the chapter highlights the importance of public education, communication, and stakeholder engagement in fostering a culture of water conservation. By utilising a portfolio of regulatory, technological, and communication-based instruments, cities can manage water demand more effectively, improve water security, and reduce the environmental impact of urban growth. Ultimately, demand management is essential for creating resilient urban water systems in the face of climate change and increasing population pressures.