Purpose <p>This study examines the association between board cultural diversity, board gender diversity, and ESG pillar performance, specifically governance and social outcomes, in European listed firms.</p> Design/methodology/approach <p>Using an unbalanced panel of 6,608 firm-year observations from 876 firms across 14 European countries over the period 2014–2024, the study employs pooled ordinary least squares (OLS), fixed-effects, and bias-corrected Least Squares Dummy Variable (LSDVC) to measure ESG pillar performance using Refinitiv governance (GPS) and social (SPS) pillar scores.</p> Findings <p>The results indicate that board cultural and gender diversity are positively associated with governance performance across the estimation models. For social performance, board cultural diversity remains statistically significant, whereas board gender diversity is significant primarily when firm-specific heterogeneity is controlled. The findings suggest that the effects of board diversity are not uniform across ESG dimensions, with stronger and more consistent associations observed for governance outcomes.</p> Originality/value <p>This study contributes to the ESG literature by adopting a pillar-specific perspective and providing a mechanism-based interpretation of how board diversity operates differently across the governance and social dimensions within a unified empirical framework.</p>