"Employee ownership has been an area of significant practitioner and academic interest for the past four decades. Yet, empirical results on the relationship between employee ownership and firm performance remain mixed. To aggregate findings and provide potential direction for future theoretical development, we conducted a meta-analysis of 102 samples representing 56,984 firms. Employee ownership has a small, but positive and statistically significant relation to firm performance ( = 0.04). The effect is generally positive for studies with different sampling designs (samples assessing change in performance pre-employee–post-employee ownership adoption or samples on firms with employee ownership), different performance operationalisation (efficiency or growth) and firm type (publicly held or privately held). Suggesting benefits of employee ownership in a variety of contexts, we found no differences in effects on performance in publicly held versus privately held firms, stock or stock option-based ownership plans or differences in effects across different firm sizes (i.e. number of employees). We do find that the effect of employee ownership on performance has increased in studies over time and that studies with samples from outside the USA report stronger effects than those within. We also find little to no evidence of publication bias."