The public sector stands out in its capacity to exert enormous purchasing power, representing 12% of GDP in OECD countries and up to 30% in developing countries, presenting a considerable potential for public procurement to be leveraged to drive a Nation’s economy towards a greener and more sustainable one. Public procurement refers to the purchases made by governments, state and semi-state-owned enterprises for goods, services and works. By building in consideration of environmental, social, and economic aspects, Green Public Procurement can help to transform markets by leveraging the power of public purchases to drive markets towards sustainability, reducing governments’ environmental footprint and contributing significantly to reductions in greenhouse gas emissions. Sustainable public procurement also allows governments to serve as an exemplary model and send strong market signals, fostering private sector and consumer behaviour change, enabling the overall transition to a green, sustainable economy.