This study investigates the impact of Green Human Resource Management (GHRM) practices on Organizational Green Innovation (OGI), emphasizing the mediating roles of Organizational Ambidexterity (OA) and Adhocracy Culture (AC), and examining the moderating effect of AC. Drawing on the Resource-Based View, Dynamic Capability Theory, and Social Identity Theory, the study explores how internal capabilities and cultural traits influence sustainable innovation in government institutions. A quantitative research design was employed using survey data collected from 395 employees at Dubai’s Roads and Transport Authority. Constructs were adapted from established scales, and the data were analysed using SmartPLS 4.0 for Structural Equation Modelling (SEM) to test both direct and indirect effects among the variables. The results demonstrate that GHRM positively influences both OA and AC, which in turn significantly enhance OGI. Both OA and AC were found to mediate the relationship between GHRM and green innovation. However, the moderating effect of AC on the GHRM and OGI link was statistically insignificant. These outcomes underscore the importance of adaptive capabilities and culture in translating green HR practices into innovation outcomes. This research contributes novel insights to the GHRM literature by focusing on the Government sector in an emerging economy context. It offers a conceptual model explaining how GHRM strategies lead to innovation via dynamic capabilities and innovation-oriented culture. The study provides actionable implications for policymakers and HR professionals seeking to institutionalize sustainability in government organizations.