Noel Cox was born in Auckland, New Zealand. After attending grammar school in Takapuna, he took up the study of law at the University of Auckland. After graduation he was admitted as a Barrister and Solicitor of the High Court of New Zealand, and later practised as a Barrister. He subsequently undertook further studies in law, canon law, and theology.Noel Cox holds the position of Professor of Law at Aberystwyth University, where he was Head of the Department of Law and Criminology 2010-2013. He was Professor of Constitutional Law (and inaugural professor of law) at the Auckland University of Technology to 2010, where he was formerly the Head of the Department of Law. He spent the summer of 2003-2004 as a Visiting Fellow in the Faculty of Law of The Australian National University, Canberra, and the latter part of 2006 at Wolfson College, the University of Cambridge. In 2009 he was elected Visiting Fellow at St Edmund's College, University of Cambridge, though he was not able to take this up as he then accepted appointment to Aberystwyth University.

Apart from New Zealand, he is also admitted to practice law in the almost all the Australian jurisdictions (the Australian Capital Territory, New South Wales, the Northern Territory, Queensland, South Australia, Tasmania and Victoria). He was called to the bar of England and Wales, by the Honourable Society of the Inner Temple. He was previously Chairman of Monarchy New Zealand (formerly The Monarchist League of New Zealand), and also a member of the Council of the Auckland District Law Society. He is a Fellow of the Royal Historical Society. He was an ordinand in the Diocese of Auckland, New Zealand, and was ordained a deacon and then a priest in the Diocese of St Davids, of the Church in Wales. He undertook training at St Michael and All Angels Theological College, Llandaff, whilst serving a placement in the parish of Llanbadarn Fawr, Aberystwyth. He is now serving his title there as Assistant Curate, now in the Group Benefice of Llanbadarn Fawr, Elerch with Penrhyn-coch with Capel Bangor. He is married.

He is the author of more than 200 academic papers, primarily in the fields of constitutional law, legal history, and ecclesiastical law, and 6 books.