ESG frameworks for smart cities: systematic review of governance, metrics and outcomes

More than half of the world’s population lives in urban areas, a share projected to reach 68% by 2050. As cities concentrate emissions, infrastructure investment and inequality, smart city models increasingly use digital technologies and data-driven management to support sustainable urban development. However, comparable evaluation across environmental, social and governance (ESG) dimensions remains unresolved. This study examines how ESG is operationalised in smart city research and proposes an integrated assessment framework. Following PRISMA 2020, searches of Web of Science and Scopus identified 84 records published between 2000 and 2026; 26 peer-reviewed studies were retained, complemented by 23 institutional documents and 10 academic book chapters. Bibliometric and thematic analyses show uneven pillar development: governance appears in 100% of studies, environmental issues in 96% and social issues in 77%. Keyword mapping yielded four clusters, and content synthesis yielded six; neither produced an autonomous social-pillar cluster. China accounts for 23% of publications, while only 27% involve international co-authorship. The study proposes a three-layer framework linking ESG pillars, governance functions and urban performance outcomes, aligned with ISO 37120, U4SSC, CITYkeys and World Economic Forum benchmarks.