Potable water reuse, transforming treated wastewater into safe drinking water, represents a critical innovation in addressing global water scarcity. Despite its technical feasibility and proven safety, public acceptance remains a significant barrier to widespread adoption. This chapter investigates the behavioural and cultural dimensions that shape perceptions of potable reuse, emphasising how trust, risk perception, and cultural norms influence acceptance. Drawing on recent research and case studies from diverse regions, the discussion highlights the role of psychological factors, including the “yuck factor,” cognitive biases, and social trust, in shaping public attitudes. It further explores how cultural narratives, religious beliefs, and community values intersect with technological solutions, often determining the success or failure of implementation. Strategies such as transparent communication, participatory governance, and education campaigns are examined as pathways to build legitimacy and foster acceptance. By situating potable reuse within broader sustainability and resilience frameworks, the chapter argues that behavioural and cultural perspectives are not peripheral but central to advancing water reuse initiatives. Future research directions are identified in cross-cultural comparative studies, digital engagement tools, and policy integration to strengthen public trust and accelerate the transition toward climate-resilient water governance.