Strategic impact assessment (SIA), also known as strategic environmental assessment (SEA), is a systematic approach to decision-making that considers the dimensions of a green economy transformation for sustainable development. Although, Namibia has made significant strides to attain the United Nations Sustainable Development Goals (UN-SDGs) 5, 13 and 15 i.e. gender equality, climate action and life on land respectively, the country seems to be struggling to meet the other aspects of the SDG targets. The chapter reviews relevant documents and analyzes results to identify the strengths, weaknesses, opportunities and threats of the current impact assessment methodologies, in the context of the UN-SDGs. Followed by a qualitative research approach, utilizing a case study design and purposive sampling technique. The target population comprised personnel from the National Environmental Affairs, Development Planning Commission, and Lands and Resettlement Authority in Namibia, key exploration of stakeholders in SEA administration. Data collection involved conducting in-depth interviews with six officers, two from each institution, using semi-structured interview guide. The findings show that Namibia undertook a voluntary SEA between 2008 and 2013, although it is not yet a legal mandate. It is evident that the drivers of SEA legislation have the potential to a green economy transformation for sustainable development with 64.3% SDG index score and 89.7% spillover score in Namibia. The level of this SDG achievement indicates the country’s commitment to SIA in land use and spatial planning policies, plans and programs for sustainable development. The research also identifies potential improvements and recommendations for a more robust impact assessment framework in guiding sustainable development. Enhanced stakeholder engagement, integrated social and economic aspects more effectively, strengthened the capacity of governments and stakeholders, and encouraged the use of SIA as a tool for development policies, plans and programs (PPPs). The study concludes that SIA plays a crucial role in guiding green economy transformation for sustainable development and that improvements can be made to enhance its effectiveness in promoting sustainable development. Keywords Agenda: Green economy, Sustainable development, Land use and spatial planning, Strategic impact assessment, Strategic environmental assessment, policies, plans and programs, Namibia.