Objective Previous research on Extraversion and life satisfaction suggests that extraverted individuals are more satisfied with their lives. However, existing studies provide inflated effect sizes, as they were based on simple correlations. In five studies, the authors provide better estimates of the relationship between Extraversion and life satisfaction. Method The current study examined student and nationally representative samples from Canada, the United States, the United Kingdom, Germany, and Japan (Study 1, N = 1,460; Study 2, N = 5,882; Study 3, N = 18,683; Study 4, N = 13,443; Study 5, Japan N = 952 and U.S. N = 891). The relationship between Extraversion and life satisfaction was examined using structural equation modeling by regressing life satisfaction on the Big Five traits. Results Extraversion was a unique predictor of life satisfaction in the North American student and nationally representative samples (Study 1, β = .232; Study 2, β = .225; Study 5, β = .217), but the effect size was weaker or absent in other non–North American samples (Germany, United Kingdom, and Japan). Conclusions The findings attest to the moderating role of culture on Extraversion and life satisfaction and the importance of controlling for shared method variance.