This working paper looks into the circular economy, its linkages with trade, and development and justice concerns related to the circular economy. The paper looks specifically into the potential for cooperation on circular economy in the World Trade Organization (WTO) and in its Trade and Environmental Sustainability Structured Discussions (TESSD). This work has benefited from collaboration with and support from the Friedrich-Ebert-Stiftung in Geneva and from comments shared by a group of various stakeholders at a meeting at Quaker House in Geneva on 24 June 2021. This is a work in progress and we welcome further comments. This is the first paper in the series on Trade and Environmental Sustainability, which also includes papers on the topics of environmental goods and services, fossil fuel subsidy reform, and greening Aid for Trade.