The Behaviour Change Wheel (BCW) is a new framework for characterising and designing behaviour change interventions. It is based on the COM-B model, which identifies three essential conditions for behaviour: capability, opportunity, and motivation. The BCW consists of three layers: the COM-B system at the center, intervention functions around it, and policy categories surrounding those. The framework was developed to address limitations of existing behaviour change frameworks, which often lack comprehensiveness, coherence, and links to a model of behaviour. The BCW was tested in two public health domains: tobacco control and obesity reduction. It was found to be reliable in characterising interventions in these areas. The framework provides a systematic way to design interventions by considering the nature of the behaviour, the mechanisms that need to be changed, and the interventions and policies required to change those mechanisms. It also allows for the identification of specific behaviour change techniques (BCTs) that can be used to achieve the desired behaviour change. The BCW is a theory- and evidence-based tool that can be used by a range of users to design and select interventions and policies. It is being developed into an intervention design tool that can be used to develop prototype strategies for specific implementation targets. The framework has the potential to improve the efficiency and effectiveness of behaviour change interventions by providing a systematic way to characterise and design them. However, there are limitations to the research, including the possibility that important frameworks may have been missed and the need for further research to develop reliable taxonomies for BCTs within intervention functions.The Behaviour Change Wheel (BCW) is a new framework for characterising and designing behaviour change interventions. It is based on the COM-B model, which identifies three essential conditions for behaviour: capability, opportunity, and motivation. The BCW consists of three layers: the COM-B system at the center, intervention functions around it, and policy categories surrounding those. The framework was developed to address limitations of existing behaviour change frameworks, which often lack comprehensiveness, coherence, and links to a model of behaviour. The BCW was tested in two public health domains: tobacco control and obesity reduction. It was found to be reliable in characterising interventions in these areas. The framework provides a systematic way to design interventions by considering the nature of the behaviour, the mechanisms that need to be changed, and the interventions and policies required to change those mechanisms. It also allows for the identification of specific behaviour change techniques (BCTs) that can be used to achieve the desired behaviour change. The BCW is a theory- and evidence-based tool that can be used by a range of users to design and select interventions and policies. It is being developed into an intervention design tool that can be used to develop prototype strategies for specific implementation targets. The framework has the potential to improve the efficiency and effectiveness of behaviour change interventions by providing a systematic way to characterise and design them. However, there are limitations to the research, including the possibility that important frameworks may have been missed and the need for further research to develop reliable taxonomies for BCTs within intervention functions.