This study aims to examine the Environmental Kuznets Curve (EKC) hypothesis in relation to greenhouse gas (GHG) emissions and economic growth across OECD countries from 1990 to 2021. The OECD provides a unique setting for this analysis due to its advanced economies, robust policy frameworks, and extensive environmental and economic datasets. Additionally, the study assesses the role of foreign direct investment (FDI) inflows and renewable energy consumption in shaping GHG emissions.