This books collects a number of papers presented during the international conference “Constitutionalism in a Plural World”, held in November of 2017 at the Porto Faculty of Law of the Portuguese Catholic University.The purpose of the conference was to incite discussion on foundational concepts of constitutional law as well as its future prospects in a globalized, multicultural and technological contemporary society. The papers gathered here demonstrate the wide range of topics covered during the event, including: constitutional amendment, popular will, democracy and party politics, free-trade agreements, multilevel protection of fundamental rights, data protection or constitutional courts.Given the undeniable constant evolutionary and transformative dynamic of constitutional law, we hope this book contributes to a better understanding of the challenges ahead.