Jonathan Ledermann trained in medical oncology and general internal medicine. He was a Clinical Research Fellow at the Charing Cross Hospital, London and a visiting Fellow at the Princess Margaret Hospital, Toronto and Ontario Cancer Institute. In 1990 he joined the Department of Oncology at University College London where he is Professor of medical oncology. He is a consultant in medical oncology at UCL Hospitals, Clinical Director of the UCL Cancer Institute and Director of the Cancer Research UK and UCL Cancer Trials Centre, one of the national cancer trials Centres in the UK.
His principal area of clinical practice and research is in gynaecological cancers. He has led many national and international clinical trials in ovarian cancer. He is a member of the ESMO Faculty, and has served on the Council for the IGCS (International Gynaecologic Cancer Society). He is the past-chair of the NCRI Gynaecological Cancer Studies Group, co-chair of the Rare Tumours subgroup of the Gynaecological Cancer Inter Group (GCIG), and was for many years a member Expert Advisory Groups for Oncology at the MHRA (Medicines and Health Regulatory Authority) and the EMA (European Medicines Agency). He is on the editorial board of three cancer journals and has lectured in many countries on his research and clinical experience.