In the twenty-first century, we face new challenges such as climate change, biodiversity loss, water scarcity, conflicts over energy and resources, depletion of scarce resources, geopolitical tensions, the struggle for human rights and economic failure, to which we must respond appropriately. Product design is increasingly expected to be not only functional and aesthetic, but also environmentally friendly. Through their design, designers influence the impact of products on the environment and society throughout their life cycle. The aim of this document is to broaden the debate on circular design, with an emphasis on the requirements of the new Eco-design Directive for sustainable products. The document presents the historical development of the environmental philosophies applied in design and describes the focus of each of them. Circular design is based on the three main principles of the “3Rs”—Reduce—Reuse—Recycle, which are an economic code of conduct. The Eco-design Directive for Sustainable Products replaces the current Eco-design Directive (2009/125/EC) and introduces more eco-design criteria for a wider range of products. It aims to make sustainable products the norm in the EU market.