Wellbeing science is the scientific investigation of wellbeing, its’ antecedents and consequences. Alongside growth of wellbeing science is significant interest in wellbeing interventions at individual, organizational and population levels, including measurement of national accounts of wellbeing. In this concept paper, we propose the capability model of wellbeing literacy as a new model for wellbeing science and practice. Wellbeing literacy is defined as a capability to comprehend and compose wellbeing language, across contexts, with the intention of using such language to maintain or improve the wellbeing of oneself, others or the world. Wellbeing literacy is underpinned by a capability model (i.e., what someone is able to be and do), and is based on constructivist (i.e., language shapes reality) and contextualist (i.e., words have different meanings in different contexts) epistemologies. The proposed capability model of wellbeing literacy adds to wellbeing science by providing a tangible way to assess mechanisms learned from wellbeing interventions. Moreover, it provides a framework for practitioners to understand and plan wellbeing communications. Workplaces and families as examples are discussed as relevant contexts for application of wellbeing literacy, and future directions for wellbeing literacy research are outlined.