Born in Birkirkara in 1934, Fenech studied at St Aloysius College and the RUM from where he qualified MD (1955). He furthered his studies in general medicine, specializing DCH (1961) and MRCP (1962). He was subsequently elected a fellow of the Royal College of Physicians (1970) and of the American College of Physicians.
Fenech held various clinical posts in medicine. He was appointed senior physician and professor of medicine in 1914, a post he held until 1977 when, because of the medical trade union dispute he took up the post of foundation professor at the University of Kuwait (1978-87). He returned to Malta in 1987 taking up the post of professor of medicine. He also served as dean to the faculty of medicine (1974-71, 1987-95) and as visiting professor at King’s College Hospital (London), the University of California, and the University of Kuwait.
Fenech has served as an examiner for the MRCP postgraduate examination and external undergraduate examiner to the University of Kuwait and Dubai Medical College. He is a member of the Association of Physicians of Great Britain and Ireland and was president to the Malta Red Cross Society. In 2001 the Maltese government in agreement with the UN secretary, appointed Fenech as a director of the International Institute on Aging of the United Nations for a period of three years.
Fenech is a member of the National Order of Merit (MOM), a magisterial knight of the Sovereign Military Order of Malta, and a knight of the Order of Isabella La Cattolica of Spain.
He is married to Mary Rose Galea.