This chapter examines demand management as a crucial strategy for attaining water and energy security in alignment with the Sustainable Development Goals (SDGs). It presents a comprehensive framework of economic, regulatory, informational, institutional, and technological instruments designed to reduce consumption, enhance efficiency, and shift usage patterns. Emphasizing cross-sectoral integration and digital innovation, the chapter highlights how demand-side approaches can optimize existing systems, improve resilience, and reduce environmental impacts. By aligning policy, planning, and behavioral tools, demand management offers a cost-effective pathway to more sustainable and equitable resource governance.