The Instituto Complutense de Estudios Internacionales (ICEI) is a research institute of the Complutense University of Madrid, Spain. Founded in 1997, it works on international studies from a multidisciplinary perspective and conducts research focused on real-world problems, addressing global challenges through innovative and collaborative approaches. 

The institute's research covers international economics and development, international cooperation, political economy, innovation, energy policy, gender, the environment and the future of Europe. It maintains stable lines of research and exchange networks with experts and international institutions and aims to influence both academic debate and public policy. ICEI also serves as a forum for open debate beyond the university and offers specialised courses in areas such as diplomacy, human rights and climate change.