Porter grew up in
South London and attended
Wilson's School in
 He won a scholarship to
Cambridge, where he studied under
J. H. Plumb.
 His contemporaries included
Simon Schama and Andrew Wheatcroft. He achieved a
double starred first
 and became a junior
Fellow in 1968, studying under
Robert M. Young and lecturing on the British Enlightenment.
 In 1972, he moved to
Churchill College as the Director of Studies in History, later becoming Dean in 1977.
 He received his doctorate in 1974, publishing a thesis on the history of geology as a scientific discipline.
 He was then appointed to the post of Assistant Lecturer in European History at
Cambridge University and promoted to Lecturer in European History in 1977.
In 1979 he joined the Wellcome Institute for the History of Medicine (part of the
University College, London) as a lecturer. In 1993 he became Professor of Social History at the Institute.
 He briefly served as its Director. In 2000, Porter published The Enlightenment: Britain and the Creation of the Modern World. He retired in September 2001, moving to
St Leonards-on-Sea, where he wanted to learn to play the saxophone, cultivate his allotment and engage in some travelling.
 He died of a heart attack five months later, while cycling.
 His memorial service was on 22 April 2002 at
St Pancras Parish Church.
He was married five times, firstly to
Sue Limb (1970), then Jacqueline Rainfray (1983), then Dorothy Watkins (1987), then Hannah Augstein, and finally his wife at the time of his death, Natsu Hattori.
He was known for the fact that he needed very little sleep.