An NHS doctor for 35 years, specializing in Geriatrics and General Internal Medicine. He has been President of the British Geriatrics Society and served on the Council of the Royal College of Physicians of London for five years, including three years as the Clinical Vice President and a member of the board of trustees. He was also President-elect of the Royal College of Physicians before having to step down due to ill health. For the past four years, he has been a Trustee of the Nuffield Trust, which specializes in health policy and health services research. 

Prof. Oliver was also the national clinical director for older people in the Department of Health from 2009 to 2013 and a visiting professor at City University. He has been a weekly BMJ columnist since 2015.