Nandasiri Jasentuliyana (also known as Jasenthu Liyana Nanadasiri de Silva) is a Sri Lankan lawyer. He was the Director of the United Nations Office for Outer Space Affairs and the Deputy to the Director-General, United Nations Office at Vienna. He was also the President, International Institute of Space Law; Executive Secretary of the UN Conference on Nuclear Energy and UN Conference on the Peaceful Uses of Outer Space.
Jasentuliyana had served as a Political Affairs Officer, Department of Political and Security Council Affairs, UN; Member, Board of Trustees of the International Space University (ISU); Member, Board of Directors of the International Institute of Air and Space Law, Faculty of Law, University of Leiden and Programme Officer, Asia Foundation.
Educated at Richmond College, Galle, he gained a LLB from the University of Ceylon and passed the law exams of the Ceylon Law College becoming an Advocate. He holds diplomas from McGill University and Academy of International and Comparative Law.