Objective: Following up on growing evidence that higher levels of conscientiousness are associated with greater health protection, the authors conducted a meta-analysis of the association between conscientiousness-related traits and longevity. Design: Using a random-effects analysis model, the authors statistically combined 20 independent samples. In addition, the authors used fixed-effects, analyses to examine specific facets of conscientiousness and study characteristics its potential moderators of this relationship. Main Outcome Measures: Effect sizes were computed for each individual sample as the correlation coefficient r, based on the relationship between conscientiousness and mortality risk (all-cause mortality risk, longevity, or length of survival). Results: Higher levels of conscientiousness were significantly and positively related to longevity (r = .11, 95% confidence interval = .05-.17). Associations were strongest for the achievement (persistent, industrious) and order (organized, disciplined) facets of conscientiousness. Conclusion: Results strongly support the importance of conscientiousness-related traits to health across the life span. Future research and interventions should consider how individual differences in conscientiousness may cause and be shaped by health-relevant biopsychosocial events across many years.