John H Lazarus is Emeritus Professor of Clinical Endocrinology at Cardiff University School of Medicine Cardiff, Wales, UK. He is a Cambridge and Glasgow graduate and was Visiting Assistant Professor, Department of Medicine, Columbia University, New York, NY. He is a past president of The British Thyroid Association and former secretary/treasurer of The European Thyroid Association.

His main interests have been in thyroid physiology and pathophysiology as well as thyroid autoimmunity. Work has focused on postpartum thyroid disease and, more recently, thyroid disease in pregnancy with emphasis on screening thyroid function in early gestation.