Purpose - School connectedness, or a sense of belonging to the school environment, is an established protective factor for child and adolescent health, education, and social well-being. While a comprehensive, whole-school approach that addresses the school organisational environment is increasingly endorsed as an effective approach to promote connectedness, how this approach creates a sense of belonging in the school environment requires systematic in-depth exploration. This paper aims to address these issues Design/methodology/approach - This study examines the influence on school connectedness of a whole-school approach to promote health in school, using a qualitative case study method. Three school communities in Southeast Queensland, Australia, are investigated as case studies in order to formulate a theoretical model of how health promotion approaches can build school connectedness. Findings - This study finds that a health promotion approach builds school connectedness by encouraging a "whole-school" orientation designed to foster interaction among members of the entire school community. Specific activities that promote interaction are school-wide activities involving the entire school community and, at the classroom level, "whole-class" activities in which students and staff work together on activities that create links between the two groups, such as collaborative curriculum planning. The "whole-school" emphasis on partnerships between staff and students and parents is also important, particularly with its focus on initiating and sustaining school-community partnerships. Originality/value - The findings are important, since they validate a whole-school approach to building school connectedness and address an important gap in the literature about how to promote school connectedness and thereby protect the well-being of children and adolescents.