Dame Marianne Griffiths was Chief Executive of University Hospitals Sussex NHS Foundation Trust, having guided Western Sussex Hospitals NHS Foundation Trust and Brighton and Sussex University Hospitals Trust through four years of joint working and a formal merger in 2021, before retiring early in 2022. She led from its creation in 2009 to becoming a Foundation Trust and in 2019 it became the first acute trust rated Outstanding in all five CQC inspected areas.

Originally from Limerick, she trained as a nurse before reading Psychology at the University of Exeter and completed Chartered Accountancy examinations with Peat Marwick (now KPMG). Her NHS career included Deputy Chief Executive and Director of Commissioning and Delivery at NHS South East Coast, Chief Executive at Kent and Medway Strategic Health Authority and roles in West Sussex as Head of Commissioning Social Services and Director of Strategic Development.

She was named the top chief executive in the Health Service Journal in 2018 and 2019, remaining in the top five until retirement in 2022. She was made a Dame Commander of the Order of the British Empire (DBE) in the 2019 New Year Honours for services to the NHS, and served as Chancellor of the University of Chichester for three years