Miran Marelja graduated from the Faculty of Law, University of Zagreb, in 2010, completing his final paper in the Department of General History of Law. He furthered his education at the Faculty of Kinesiology, University of Zagreb, graduating in 2013 with a degree in Economics and Sports Management, and also earning the academic title of teacher of physical education and health culture, along with additional qualifications in basic kinesiological transformations.
Following his professional sports and coaching career, Marelja transitioned to the banking sector. In 2011, he joined the Department of General History of Law and State at the Faculty of Law, University of Zagreb, as an assistant. He later continued as a postdoctoral researcher. That same year, Marelja enrolled in the postgraduate university study of Legal Sciences, specializing in International Public and International Private Law, completing the programme in 2017.
Marelja earned his Doctor of Science degree in the field of Social Sciences, specializing in the History of Law and State, with his doctoral dissertation titled “Historical Development of Constraints on Conducting International Armed Conflicts.” During his doctoral studies, he developed a keen interest in the legal-historical aspects of international law, particularly in the fields of war (humanitarian) and diplomatic law, as well as the evolution of subjectivity in international law, adeptly linking historical legal matters with contemporary legal issues.