The Environmental Social Science kNowledge Exchange Map of Opportunities (ESS NEMO) is a package of systems maps and associated documentation that show the groups, organisations and individual actors that environmental social scientists could engage with in knowledge creation and/or exchange in the UK. ESS NEMO is a tool that, among other rationales, aims to promote greater collaboration and trust between environmental social scientists, and with other groups that may not traditionally be included in ESS activities. Environmental Social Science (ESS) is defined as the systematic study of people and their social and their non-human physical environment (their habitat) (Gatersleben et al., forthcoming). The information presented in ESS NEMO reflects the situation as of 10th July 2024. It is acknowledged that the landscape is dynamic, and changes frequently over time.