Professor Kelleher, currently the Vice-Provost for Medical Affairs and Head of the School of Medicine at Trinity College Dublin, has over 30 years' experience in research, teaching and medical leadership. He takes up the new role on 1 October 2012.
He will direct the Faculty of Medicine's activities, and will be a member of the College's Management Board, its senior decision-making body.
Imperial's Faculty of Medicine is one of Europe's largest higher education medical institutions with over 1,000 students, more than 2,300 staff and a research income of more than £140 million.
In the Times Higher Education World University Rankings 2010-11 Imperial was ranked third in the world for clinical, preclinical and health subjects.
Professor Kelleher succeeds Professor Sir Anthony Newman Taylor, who has been Principal since December 2010.
Welcoming the appointment, Rector Sir Keith O'Nions said: "Professor Kelleher is an international leader, with an outstanding record in academic medicine. His emphasis on translating research discoveries from the laboratory to frontline patient care fits perfectly with Imperial's vision, and I am delighted to welcome him to the College."
Professor Dermot Kelleher said, "Imperial's Faculty of Medicine has an international reputation for excellence and a global reach that I have long admired. I share in its vision for research translation, both through its activities in the Academic Health Science Centre and the future partnership with health providers in North West London. A huge strength of Imperial is the opportunity to build links between medicine and its other academic disciplines - engineering, science and business. I look forward to collaborating with all colleagues across the College to further strengthen Imperial's medical research and teaching activities and help take the Faculty to new heights."
Graduating in medicine from Trinity College Dublin in 1978, Professor Kelleher completed specialist training in gastroenterology and subsequently received a Fogarty Scholarship in 1986 funding a research fellowship at University of California San Diego.
He returned to Trinity in 1989 as a Wellcome Senior Fellow in Clinical Science and was appointed to the Trinity College Chair in Clinical Medicine in 2001. In 2006 he was appointed Head of the School of Medicine and Vice-Provost for Medical Affairs.
Professor Kelleher's research examines the immune response to many of the leading causes of gastrointestinal infectious disease worldwide, including organisms such as Helicobacter pylori and Clostridium difficile.
A focus of his work has been using tools derived from cell biology to analyze the function of the lymphocyte, a type of white blood cell, in the body's response to infectious agents and inflammatory diseases, such as inflammatory bowel disease.
Professor Kelleher was instrumental to the founding in 2002 of the Dublin Molecular Medicine Centre, a joint venture between the three major medical schools and their associated academic hospitals in Dublin aimed at accelerating the translation of biomedical research into improved diagnostics and therapies for patients.
Known as Molecular Medicine Ireland since 2008 this not-for-profit company has provided both a corporate and a physical infrastructure to support significant developments in medical biotechnology in Ireland.
The author of over 200 publications and 14 patents, Professor Kelleher is a founding member of Opsona Therapeutics, a spin out company at Trinity College Dublin which identifies new ways to prevent and treat autoimmune/inflammatory conditions, cancers and infectious diseases.
Professor Kelleher has just completed his term as Chairman of the Eurolife Consortium of European Medical Schools, and has served as a member of the Board of the Health Research Board Ireland, the European Medical Research Council and the Wellcome Trust Clinical Interest Group.
A Fellow of the Academy of Medical Sciences, Royal College of Physicians of Ireland, Royal College of Physicians (London), Trinity College Dublin, and the American Gastroenterology Association, he was awarded the 2011 Conway Medal by the Royal Academy of Medicine in Ireland.
A longer biography is available in Notes to Editors below and a photograph of Professor Kelleher is available on request.