This study aimed to systematically synthesize and quantitatively analyze empirical evidence on the antecedents and outcomes of Green Human Resource Management (GHRM) to provide an integrated theoretical and practical framework. This research employed a quantitative meta-analytic design. Data were drawn from 25 empirical studies published between 2016 and 2022 in both Persian and English academic databases. Studies were included if they focused on GHRM antecedents or outcomes, reported quantitative effect sizes, and demonstrated acceptable methodological quality. Random-effects modeling was used to estimate pooled effect sizes with Comprehensive Meta-Analysis software (version 3). Heterogeneity was assessed with Q and I² indices, while publication bias was examined using funnel plots, Egger’s regression test, and Rosenthal’s fail-safe N. Results indicated that the strongest antecedents of GHRM were green organizational culture (r = 0.52), green leadership (r = 0.55), and top management commitment (r = 0.48). On the outcome side, employee green behaviors (r = 0.47), organizational environmental performance (r = 0.43), and organizational commitment (r = 0.42) emerged as the most robust effects. The Q test and I² index revealed very high heterogeneity (I² = 99.99%), underscoring the influence of contextual moderators such as cultural and industrial settings. Publication bias analyses suggested that the findings are reliable and stable. GHRM significantly contributes to enhancing organizational sustainability and fostering pro-environmental employee behaviors. Despite high heterogeneity, the findings highlight the need for localized strategies to implement GHRM effectively in specific contexts, such as resource-constrained and culturally distinct environments like Iran. The study advances theoretical development and offers actionable insights for managers and policymakers aiming to integrate sustainable HRM practices.