Biography
Denis Kierans is a Research Affiliate at the University of Oxford’s Centre on Migration, Policy and Society (COMPAS) and a visiting academic at the Spanish National Research Council's Institute of Economics, Geography and Demography in Madrid.
At COMPAS, he is a part of the 17-partner consortium leading the Measuring Irregular Migration and Related Policies (MIrreM) project, a follow-up to the seminal Clandestino project (2009). In it, he coordinates the collection, assessment and dissemination of estimates of the irregular migrant population across Europe and North America. He is the lead author of the MIrreM Public Database on Irregular Migration Stock Estimates and the report, The Irregular Migrant Population of Europe. He is currently co-editing a handbook on the use of irregular migration data in policymaking.
From 2019 to 2024, he was a Senior Researcher at the Migration Observatory and the Global Exchange on Migration at Diversity at COMPAS.
Denis presents his academic findings in a variety of fora, both for academics and the general public, and contributes to such initiatives as the International Migration Research Network (IMISCOE), including teaching at its 2025 Spring School.
Previously, he was a Data and Research Officer at IOM’s Global Migration Data Analysis Centre in Berlin. In this role, he co-authored the Guidelines for the Harmonization of Migration Data Management in the ECOWAS Region, which was disseminated across West Africa and is helping to lay the groundwork for improved production and sharing of migration data in the region and beyond.
Denis holds a Master's degree from the University of Toronto’s Munk School of Global Affairs, where he focused on the movements of vulnerable groups in the EU and Russia.
