Willem Maas, Jean Monnet Chair and Professor of Political Science, Public & International Affairs, and Socio-Legal Studies at York University, chaired Glendon Political Science for three and a half years, Glendon Faculty Council for four, and is also active in professional service, including currently serving on the executive of the European Community Studies Association Canada and IPSA's Migration and Citizenship RC and remaining active in APSA's Migration and Citizenship section, which he co-founded. Professor Maas has held appointments at Yale, NYU, Radboud, Leiden, EUI, and elsewhere, and writes on EU and multilevel citizenship, migration, borders, free movement, and politics focusing on Europe and North America. He co-edits the Oxford Studies in Migration and Citizenship book series and also heads the Canadian part of the Whole-COMM project, investigating the integration of migrants in small communities. In 2022/23, Maas is York Massey Fellow at Massey College.

Money Matters in Migration (co-ed 2021). Eighteen chapters expose hidden and sometimes contradictory policy objectives, unwanted consequences, and inconsistent regulatory structures of migration, participation, and citizenship.

Sixty-Five Years of European Governance (co-ed 2016). Eleven articles demonstrate the creative and often fragile solutions found to address the challenges facing Europe by analyzing transformations in European governance.

Multilevel Citizenship (ed 2013) disputes the dominant narrative of citizenship as a homogeneous status bestowed only by nation-states; it considers overlapping jurisdictions, sub- or supranational citizenships, and shared governance.

Democratic Citizenship and the Free Movement of People (ed 2013) challenges the normal way of thinking about free movement by identifying barriers and disincentives to free movement, against citizenship's promise of equality.

Creating European Citizens (2007) argues that European integration involves not only economic cooperation but also a political project of transcending borders and building a European community of people.