Jonathan E. Fielding M.D., M.P.H., M.A., M.B.A. is the Director of the Department of Public Health and is the Health Officer for Los Angeles County. In his position of Director Dr. Fielding oversees public health activities, including those for environmental health, disease control, health education, health assessment, and chronic diseases. As Director of one of the largest health departments in the United States, Dr. Fielding has led efforts to developed plans to deal with emergencies related to bioterrorism, pandemic flu, and other emerging diseases and conditions. He also has called attention to the underlying health determinants: the physical and social environments in which we live. Dr. Fielding also serves as Commissioner and vice-chair of the First 5 L.A. Commission, whose aims are to improve health and development of children 5 years of age and under.

Dr. Fielding has been a founding member of a number of national task forces that assess best evidence and make recommendations to improve the health of the public. These include the U.S. Clinical Preventive Services Task Force and the U.S. Community Preventive Services Task Force, which he chairs. Dr. Fielding is a Professor in both the UCLA School of Medicine and the UCLA School of Public Health where he is currently the principal investigator of the Health Forecasting project. Dr. Fielding has published on a wide range of public health as well as preventive medicine issues. He has authored over 160 peer-reviewed articles, chapters and editorials. He has served as Editor of the Annual Review of Public Health, Chairman of the national Partnership for Prevention, a Board Member of the American Legacy Foundation, and an elected member of the National Academy of Sciences Institute of Medicine. In 2006 he received the American Public Health Association (APHA)’s oldest and most prestigious award, the Sedgwick Memorial Medal for Distinguished Public Health, at the 134th APHA Annual Meeting & Exposition. In 2008, he was appointed by the Secretary of Health and Human Services Michael Leavitt to chair the Secretary’s Advisory Committee on the 2020 Health Objectives for the Nation. He was also appointed to the California Department of Public Health Advisory Committee.

Dr. Fielding's previous appointments include; Director, Division of Peer Review, Bureau of Quality Assurance, Health Services Administration, Department of Health, Education and Welfare. Commissioner of Public Health, Commonwealth of Massachusetts, Co-Director, Center for Health Enhancement Education and Research, University of California, Los Angeles He has also served as a Vice President of Johnson & Johnson.