Knowledge management practices (KMP) are critical to improving the humanitarian supply chain (HSC) performance and globally adopted sustainable development goals (SDGs). However, organizations involved in HSC have not realized the full potential of KMP. Numerous factors influence the adoption of KMP in HSC. However, from a strategic and global development perspective, refining and prioritizing these factors is essential to increase practical benefits, as some factors hold greater significance than others. Moreover, evaluating the importance of these factors involves the subjectivity of human judgment. Therefore, this study combines the fuzzy set theory and the decision making trial and evaluation laboratory (DEMATEL) method to identify, evaluate, and develop a novel structural cause-and-effect model to identify the critical success factors (CSFs) that influence KMP. In this study, a fuzzy DEMATEL questionnaire was developed to collect data from experts in the field. This study identified seven CSFs out of 14 factors influencing KMP in HSC. The CSFs include top management support and commitment, a solid organizational culture based on knowledge sharing, an appropriate feedback mechanism, government support and involvement, donor support, easy-to-use information and digital technologies, and the development of information disclosure policies. The paper closes with a discussion of how these factors interact with each other and their impacts on KMP. The paper also discusses the theoretical and managerial implications.