Drawing on Governance Theory and institutional perspectives, this study analyses the relationship between e-government use and SDG16-related institutional outcomes across 27 European countries during 2010–2022. Using longitudinal panel data estimations with country and year fixed effects, complemented by an exploratory cluster analysis, the paper examines how technological, economic, and demographic factors influence trust in public institutions, voice and accountability, and control of corruption. The results reveal substantial heterogeneity across institutional dimensions. Economic variables, particularly income per capita and unemployment, emerge as the most robust predictors of institutional performance. By contrast, the effects of technological variables weaken considerably once structural country heterogeneity is controlled for. The findings suggest that digitalisation is more strongly associated with institutional trust than with improvements in democratic accountability or corruption control. Cluster analysis identifies heterogeneous trajectories of e-government adoption across European countries, indicating that digitalisation does not automatically generate governance improvements in all contexts. Overall, the study shows that the effectiveness of e-government depends heavily on broader institutional and socio-economic conditions and highlights the importance of distinguishing structural cross-country differences from within-country longitudinal dynamics.