Objective. Self-esteem may be adversely affected in adults with overweight or obesity, particularly women and those showing higher BMIs, although there is no consensus in the literature. The objective of the current study, based on reported cross-sectional associations, was to clarify the relationship between global self-esteem and overweight/obesity in adults. Methods. Four databases were searched to identify eligible literature published prior to June 2024, and a systematic review was conducted of the 120 articles identified. Meta-analytic processing of 38 eligible articles at the study level and of the participant data obtained from 16 studies (n = 2,972) was conducted for quantitative synthesis. Potential moderators, such as gender, age, BMI, type of assessment, and treatment-seeking status, were tested. Results. The summary correlation between BMI and self-esteem across studies was r = -.11, 95% CI [-.17, -.05], z = -3.70, p < .001. None of the tested moderators affected this association, although the meta-analysis of the individual participant data provided by the authors revealed a small effect of gender and a non-linear evolution of self-esteem linked to BMI. Conclusion. The present study found a negative relationship between global self-esteem and verweight/obesity in adults, which suggests a negative, although weak, effect of excess weight on self-perception.