<p>One Health has gained traction as an essential transdisciplinary approach to understanding and managing issues that are concurrently relevant to human, animal, plant, and ecosystem health. Given that all life is critically dependent upon a reliable supply of water of acceptable quality, it follows that water science and management should feature prominently within the One Health agenda. However, One Health remains narrowly focussed on traditional issues such as infectious diseases, zoonosis, antimicrobial resistance, and food safety. Despite an expansion in the rhetoric and scope of One Health in recent years, there has been limited integration of environmental issues, including water-related research and management. There are nevertheless several areas in which One Health and water science and management overlap, each of which reveal important knowledge gaps and opportunities for future research. This article provides a contemporary review of One Health and explores these areas of intersection, arguing that there is a need for improved transdisciplinary research to strengthen water’s place in the One Health agenda. It considers current advances in the One Health framework, providing an overview of the definitions, fundamental principles, and scope. Specific opportunities for water-related research within the One Health framework are also discussed.</p>