This research develops a set of specific modern slavery disclosure principles for organisations. It critically evaluates seven legislative Acts from five different countries and 16 guidelines and directives from international organisations. By undertaking an in-depth content analysis, the research derives an index comprising nine principles and 49 disclosure items to promote best-practice disclosure in tackling modern slavery. We promote nine active principles for organisations to implement and disclose: recognising modern slavery practices, identifying risks, publishing a modern slavery risk prevention policy, proactive in assessing and addressing risks, assessing efficacy of actions, garnering internal and external oversight, externally communicating modern slavery risk mitigation, implementing a suppliers’ assessment and code of conduct to ensure transparency and specifying consequences for non-compliance. The research is motivated by the United Nations Sustainable Development Goal 8, which focusses on economic growth, full and productive employment and decent work. The research findings will assist practitioners seeking to discover and disclose evidence of modern slavery practices and their mitigation to minimise and encourage the elimination of this unethical and illegal practice in domestic and global supply chains and operations.