The Saudi Green Initiative (SGI) represents a major national effort to enhance environmental sustainability and urban livability in Saudi Arabia. Despite its ambitious targets, limited empirical research has evaluated its spatial performance and social impacts. This study assesses the progress of SGI implementation in Riyadh by examining the spatial distribution, accessibility, and equity of urban green spaces (UGS), alongside residents’ perceptions of their quality. A mixed-methods approach was adopted, integrating Geographic Information Systems (GIS)-based spatial analysis with a structured survey of 180 residents. Spatial indicators were evaluated against the World Health Organization (WHO) benchmark of 9 m² per capita and the SGI target of 28 m² per capita. The results reveal that although total green space has increased between 2018 and 2024, its distribution remains uneven, with high-density neighborhoods consistently falling below recommended standards. Survey findings indicate high satisfaction with recreational and environmental benefits, but lower satisfaction with facilities and public engagement. The study highlights that increasing total green space alone does not ensure equitable access and emphasizes the need for population-sensitive planning strategies. These findings provide practical insights for improving the spatial equity and effectiveness of urban greening initiatives and contribute to broader sustainable urban development goals.