This timely Research Agenda explores how international investment law is evolving in response to economic, technological, and environmental changes. It addresses the balance between protecting foreign investors’ rights and allowing states to regulate important public matters such as public health, environmental protection, and human rights. Leading experts in the field discuss the complexities of investor-state disputes, how these disputes impact global legal frameworks and future directions for system reform. Topics including the digital economy, environment protection, human rights, public health, dispute prevention, property law, the perspective of the Global South, the judicialisation of dispute mechanisms and the importance of transparency in arbitration for public trust are analysed in depth. By examining both traditional and emerging challenges, contributing authors canvass the ways to reform investment law to be fairer and more effective in light of global challenges and outline issues to be explored further in future research. Interdisciplinary in scope, A Research Agenda for International Investment Law is an important resource for academics, researchers and students of economic law, trade law and international investment law. Legal practitioners, policymakers, economists, political scientists, human rights and environmental advocates, and government officials will also benefit from the book’s practical insights.