Catherine Day is a former Secretary General of the European Commission, a post she held from 2005 to 2015. She is the first woman to hold this post. Prior to her appointment as Secretary General she was Director General for Environment. She worked in the external relations department of the European Commission as deputy Director General, reporting to Chris Patten. She worked on the future enlargement of the EU in the 1990s and was one of the architects of the pre-accession process for the countries of central and eastern Europe. Catherine worked in the Cabinets of Commissioners Richard Burke, Peter Sutherland and Leon Brittan and joined the European Commission in 1979.
She has a B.A in economics and politics and an M.A. in international trade from UCD. She holds honorary doctorates from UCD and University of Limerick.
Catherine now chairs the Governing Body of University College Cork and the Board of Trustees of the Chester Beatty Library. She is on the board of the European Movement Ireland, the Institute of International and European Affairs in Dublin and the Irish Times Trust. She was a special adviser to the former resident of the European Commission, Mr Jean-Claude Juncker until 1 December 2019. She was elected to membership of the Royal Irish Academy in 2016. In 2017/2018, at the request of the Minister for Health, she chaired an independent review group to examine the role of voluntary organisations in publicly funded health and personal social services in Ireland.