<p>Social sustainability is a crucial yet underexplored dimension of sustainability. Although often referenced alongside environmental and economic sustainability, its meaning remains ambiguous. Given that education is frequently seen as a key driver of sustainability transitions, this review examines how social sustainability is conceptualised in educational research. We analyse journal articles that address social sustainability and education with a view to understanding (1) the extent to which social sustainability has been conceptualised, (2) the societal challenges or predicaments these conceptualisations respond to and (3) the different ways in which social sustainability is framed. Out of the 98 journal articles we examined, 38 provided an explicit definition of social sustainability. We analyse the extent to which these conceptualisations are shaped by geographical, educational and disciplinary contexts, as well as the challenges they address. Further, we identify five key foci: (1) equity and belonging, (2) diversity, (3) life quality, (4) basic needs, and (5) growing together beyond the human species. The latter focus introduces a more-than-human perspective and expands traditional definitions by addressing anthropocentrism as a sustainability challenge. This review contributes a set of dimensions that shape how social sustainability is conceptualised as a context-dependent concept within education. Crucially, definitions should be grounded in the challenges or predicaments they seek to address; a connection that is often missing in the existing literature. By identifying how current studies situate social sustainability in relation to such predicaments, this review highlights opportunities to strengthen this connection in future work.</p>