Simon Mateus is a researcher for Professor Christof Heyns, Member of the UN Human Rights Committee. He is also the National Co-ordinator of the National Schools Moot Court Competition. He completed his LLB at the University of Pretoria in 2020, and is currently enrolled for an LLM in International Law with Professor Dire Tladi at the University of Pretoria and the focus area of his research being the issues surrounding the hierarchy in the governance of international law.

Simon was part of the first South African team to win the International Schools Moot Court Competition and has gone to win various international moot court competitions with the UP Law faculty, including the Manfred Lachs International Space Law Moot Court Competition, where he (and his team), won the international championship in 2018, the first win for the African Continent in 27 years, as well as the Phillip C. Jessup International Moot Court Competition, with his team winning the Alona E Evans award for the 15th place Best Combined Memorials globally. Simon has coached and judged various moot court competitions. In addition to his participation in moot court competitions, as an undergraduate, he was also a member of the Constitutional Tribunal of the University as well as the Editor-in-Chief of the Pretoria Student Law Review.

His main research interests include: International Law, Human Rights Law and Commercial Litigation.