Artificial Intelligence (AI) is rapidly transforming and reshaping social institutions, work patterns, and day-to-day life. Although previous research has largely focused on the economic efficiency and technological benefits of AI-enabled transformation, its implications for social responsibility remain underexplored and under-theorised. This conceptual paper investigates how AI transformation influences social sustainability across different social domains, including work settings, education, governance, and social inclusion. By applying social sustainability and socio-technical systems theories, this paper identifies key ethical mechanisms through which AI-enabled digital transformation affects social sustainability outcomes. This paper also presents an integrated conceptual model that illustrates the relationships between AI-driven transformation and social sustainability outcomes, through some mediating mechanisms such as algorithmic fairness, transparency, accountability, workforce well-being, and the distribution of social benefits and risks associated with AI adoption. This review further highlights how uneven AI access to AI and digital infrastructure is, particularly in global south contexts, which vary significantly. This paper contributes to social science scholarship by advancing a theory-informed conceptualisation of social sustainability of AI-enabled digital transformation. It further highlights the need for comparative and global south-focused studies to capture the uneven social consequences of AI adoption in institutional contexts. This study also offers practical implications for organisations and policymakers to adopt ethical responsibility and social sustainability in AI-driven digital transformation.