Framed by a social practice perspective, this article presents a theoretical, political, and practical rationale for implementing and expanding water, sanitation and hygiene education (WASH) in preschools throughout the world. Every day thousands of young children die, while others suffer serious illness or stunting from water-, sanitation-, and hygiene-related causes. Many of these consequences could be prevented with low-cost interventions. Although there is little peer-reviewed research on preschool WASH, justifications and ideas for action can be found in the results of WASH studies in primary schools. Pre-primary education and WASH are priorities within the global Sustainable Development Goals (SDG) for 2015-2030. Numerous materials and methods from school-based WASH can be used or adapted for preschool. However, early childhood and WASH professionals and advocates must launch preschool initiatives and also advocate for incorporation of WASH curricula into pre-service and in-service teacher education. More research needs to be conducted on outcomes of WASH-focused experiences in preschool. Advocacy actions with governments, UNICEF, NGOs, and other organizations can ensure that aspirations and good intentions for WASH initiatives are realized, but such progress will require adequate funding.