<p>Entrepreneurial success is often linked to psychological traits, yet the specific role of optimism remains insufficiently understood in entrepreneurship research. Addressing this gap, our meta-analysis investigates how optimism influences entrepreneurial outcomes by examining its relationship with key entrepreneurial variables. The results indicate that entrepreneurs possess higher levels of optimism compared to non-entrepreneurs (<i>δ</i> = 0.36). Furthermore, the study reveals positive associations between optimism and three critical variables: entrepreneurial intention (<i>ρ</i> = 0.36), performance (<i>ρ</i> = 0.28), and well-being (<i>ρ</i> = 0.47). Relative importance analysis identifies optimism as the second most influential factor in explaining variance in entrepreneurial intention—ranking below risk propensity but above the Big Five personality traits. Additionally, when explaining variance in performance, optimism outperforms other factors, emerging as the most influential contributor. Notably, the relationship between optimism and entrepreneurial performance varies across different measures, with stronger correlations observed in self-reported and financial performance. These findings underscore the theoretical significance of optimism as a crucial psychological trait in entrepreneurship.</p>