He was Professor of History and Vice-Chancellor Emeritus (Vice-Chancellor 1990–1994) at the University of California, Berkeley, senior research fellow at Worcester College, Oxford, and visiting professor at Yale University and the California Institute of Technology.
He edited the academic journal Historical Studies in the Physical and Biological Sciences for twenty-five years.
[1] In additition to his university work, Heilbron authored over 20 books primarily dealing with the history of science; they included studies of phenomena such as geometry, electricity and quantum physics, as well as biographies of scientists such as Galileo and Max Planck.
[4] His approach saw him investigating the influence of politics, personalities and institutions on the emergence of new scientific ideas.
[2] His study of the relationship between the church and science, The Sun in the Church: Cathedrals as Solar Observatories, was awarded the profession's highest prize for specific works, the Pfizer Award from the History of Science Society.