SummaryDebates about the utility of conscientiousness as a predictor of job performance have focused primarily on mean effect size estimates, despite theoretical and empirical reasons to expect variability across situations. The present study meta-analytically demonstrates that occupation-level situational strength is one important source of this variability. Consistent with theory, predicted uncorrected conscientiousness-performance correlations ranged from r ¼ .09 to .23 (overall performance) and r ¼ .06 to .18 (task performance), with stronger correlations observed in weak occupations. These results highlight the need for continued inquiry into the nature of situational strength, its impact on other predictor-outcome relationships, and the implications of these issues vis-à-vis theory and practice.