Muireann holds bachelor's and master's degrees in economics from Trinity College Dublin and the University of Oxford respectively. From there she worked with strategy consultants, McKinsey & Co, across the Australian & New Zealand and the UK & Ireland regional complexes. Prior to joining the Group, she was Director of Group Strategic Growth Initiatives at Glanbia plc, a global nutritionals group headquartered in Ireland. Her career at Glanbia from 2004 to 2017 involved a progression of strategy and development roles, spanning B2C and B2B platforms, at central and divisional levels and with particular focus on Glanbia's North American activities.
She is a board member of Trinity Brand Commercialisation Services Ltd, a subsidiary of Trinity College Dublin. She is a member of the Ireland Council at the University of Notre Dame. She is a long-time strategic advisor to Other Voices, an international music and cultural festival and media platform. She is a co-founder of Ireland's Edge, an interdisciplinary conference interrogating the merging of the arts, technology, industry and education in Ireland.