This online course introduces the fundamental concepts of Household Water Treatment and Safe Storage (HWTS) through engagement with interactive e-learning modules, quizzes, and links to supplementary resources. Throughout the modules, the importance of capacity building and context analysis in ensuring successful HWTS implementation is highlighted. This course provides an introduction to drinking water quality, the Multi-Barrier Approach to safe drinking water, household water treatment and safe storage (HWTS) options, behavior change, and implementation best practices. It is intended for people responsible for making decisions about HWTS.