The effective and integrated response to critical contemporary global challenges, including sustainable recovery from the adverse effects of the pandemic crisis, depletion of natural resources, climate change and green transition, requires the adoption of coherent and forward-looking public policies and comprehensive implementing means and criteria. It necessitates the establishment of sustainable financing instruments and the reorientation of economic activities and investments into projects and actions that promote sustainable, resilient and inclusive growth. The utmost objective of this article is to highlight the fundamental principles, primary objectives and key financial aspects of the regulatory regime established by the EU Taxonomy Regulation, governing the classification of the environmentally sustainable economic and investment activities within the European Union. A detailed examination of the EU Taxonomy Regulation allows useful conclusions to be drawn about the form, content and multi-dimensional nature of the criteria and conditions on the basis of which the degree of environmental sustainability of public policies which set environmentally sustainable standards and requirements, and economic activities and investment projects based on them, are laid down and determined. Particular emphasis is placed on capturing and sketching the contribution a uniform system for classifying environmental economic activities can make to meeting a set of critical environmental goals and priorities set at global and EU level, relating to climate change mitigation and adaptation, protection and restoration of biodiversity and ecosystems, sustainable use of natural resources, and the circular economy. Drawing methodologically on the examination of the EU Recovery and Resilience Facility (RRF) and its consistency and interlinkages with the primary objectives and principles of the EU Taxonomy Regulation, the article seeks to enrich the scholarly debate and explore the extent and the degree to which key environmentally sustainable criteria, standards and requirements, are reflected and integrated in the process of designing, formulating and assessing structural reforms and public investments to be embedded in the national recovery and resilience plans of the EU Member States.