Nikola Mandić was born in 1985 in Split, Croatia. He finished elementary and Nautical High School in Split. He graduated from the Faculty of Maritime Studies, University of Split, in 2007 at undergraduate studies in Maritime Management and got the degree of a maritime transport engineer. He completed a post-graduate course in the Maritime Law and Law of the Sea at the Faculty of Law, University of Split, in 2010 and received a Master’s degree. He completed post-graduate doctorate studies in the field of Legal Sciences at the Faculty of Law, University of Mostar, in 2015. His doctoral thesis was titled: Liability of the Carrier in the Carriage of Goods by Sea with Special Reference to the Rotterdam Rules 2009. He acquired the doctoral degree (Ph. D.).
He has been employed at the Faculty of Maritime Studies, University of Split, as an assistant (from 2008), postdoctoral researcher (from 2015), assistant professor (from 2016), and associate professor (from 2022) in maritime law courses. From 2021 he is Vice-Dean for Student and Academic Affairs at the Faculty of Maritime Studies, University of Split. He has been a mentor for over hundred undergraduate and graduate theses.

He participated in thirty scientific conferences and has also published around fifty scientific papers on maritime law and maritime traffic (legal aspects of navigational safety, maritime contracts, averages, environmental protection law, public transport in coastal liner shipping etc.). He has cooperated in scientific and professional projects in the field of maritime law, maritime transport, maritime management etc. He is the head of the Erasmus+ project Upgrading and harmonization of Maritime law STCW based curriculum for Maritime students (MareLaw).
He is entered in the Scientists Registry under no. 301594. He is a member of Croatian Association of Maritime Law and Economy Jurist Association Split.