Professor Dermot O’Reilly is a clinical academic professor of social epidemiology within the Centre for Public Health at Queens University Belfast. His primary research ambition is to increase the utilisation of routine administrative data to advance understanding of ill-health at a societal level and effect policy change. He was the originator of the Northern Ireland Mortality Study and co-originator and first Director of the Northern Ireland Longitudinal Study (NILS). He is currently PI and Director of the Administrative Data Research Centre for Northern Ireland (ADRC-NI) and Operations Director the Northern Ireland ageing cohort (NICOLA). Within DataMind, DOR acts as Chief Data Officer, overseeing all aspects of work in relation to data acquisition, curation, governance and access supported by the Belfast PM. Although interested in understanding the interplay of social factors and mental health, his current focus is on studying social excluded and hard to reach groups, and on using outputs from research based on linked administrative data to stimulate cross-departmental discussion and policy development.